DCVT - Teledyne Hastings Instruments

DCVT - Teledyne Hastings Instruments
TELEDYNE
HASTINGS
INSTRUMENTS
INSTRUCTION MANUAL
DCVT
(DIGITAL CVT)
ISO 9001
C E R T I F I E D
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Manual Print History
The print history shown below lists the printing dates of all revisions and addenda created for this
manual. The revision level letter increases alphabetically as the manual undergoes subsequent updates.
Addenda, which are released between revisions, contain important change information that the user
should incorporate immediately into the manual. Addenda are numbered sequentially. When a new
revision is created, all addenda associated with the previous revision of the manual are incorporated into
the new revision of the manual. Each new revision includes a revised copy of this print history page.
Revision A (Document Number 173-102008)............................................................................ October 2008
Revision B (Document Number 173-022009) .......................................................................... February 2009
Revision C (Document Number 173-072009) .................................................................................. July 2009
Revision D (Document Number 173-102009) ........................................................................... October 2009
Revision E (Document Number 173-082010) ..............................................................................August 2010
Revision F (Document Number 173-012011) ............................................................................. January 2011
Revision G (Document Number 173-032011) ............................................................................. March 2011
Revision H (Document Number 173-122011) ....................................................................... December 2011
Revision J (Document Number 173-012013) .............................................................................. January 2013
Revision K (Document Number 173-022013) ......................................................................... February 2013
Revision L (Document Number 173-012014) ............................................................................. January 2014
Visit www.teledyne-hi.com for WEEE disposal guidance.
CAUTION: The instruments described in this manual are designed for INDOOR use only.
CAUTION:
The instruments described in this manual are designed for Class 2 installations
in accordance with IPC standards
Teledyne Hastings Instruments reserves the right to change or modify the design of its
equipment without any obligation to provide notification of change or intent to change.
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Table of Contents
1. GENERAL INFORMATION......................................................................................................................................... 4 1.1. 1.2. 1.3. 1.4. 1.4.1. 1.4.2. 2. INSTALLATION ............................................................................................................................................................ 8 2.1. 2.2. 2.3. 2.4. 2.5. 2.6. 2.7. 2.8. 2.9. 3. DIGITAL CVT, OUTLINE DIMENSIONS ........................................................................................................... 8 DIGITAL CVT, FRONT PANEL ........................................................................................................................... 8 DIGITAL CVT, BACK PANEL ............................................................................................................................. 9 PANEL MOUNTING ............................................................................................................................................. 9 DIGITAL CVT-33D, OUTLINE DIMENSIONS ................................................................................................. 10 TERMINAL BLOCK ............................................................................................................................................ 10 RELAY CONNECTION ....................................................................................................................................... 11 DIGITAL CONNECTION .................................................................................................................................... 11 ANALOG OUTPUT CONNECTION ................................................................................................................... 11 VACUUM GAUGE OPERATION .............................................................................................................................. 13 3.1. 3.2. 3.3. 3.4. 3.5. 3.6. 3.7. 3.8. 3.8.1. 3.8.2. 3.8.3. 3.8.4. 3.9. 3.10. 3.11. 3.11.1. 3.11.2. 3.12. 3.13. 3.14. 3.14.1. 3.14.2. 3.14.3. 3.14.4. 3.14.5. 3.14.6. 3.14.7. 4. FEATURES ............................................................................................................................................................ 4 SPECIFICATIONS ................................................................................................................................................. 5 SAFETY ................................................................................................................................................................. 6 ACCESSORIES ...................................................................................................................................................... 6 INSTALLATION ACCESSORIES ........................................................................................................................ 6 CALIBRATION REFERENCE TUBES ................................................................................................................. 6 AC INPUT POWER .............................................................................................................................................. 13 QUICK START..................................................................................................................................................... 13 PRESSURE MEASURMENT .............................................................................................................................. 13 OPERATION AND PERFORMANCE ................................................................................................................ 13 GAUGE TUBE OPERATING PRINCIPLE ......................................................................................................... 14 LINEAR OUTPUT SELECTION ......................................................................................................................... 14 TUBE SELECTION .............................................................................................................................................. 15 CALIBRATION PROCEDURE ........................................................................................................................... 15 PREPARATION ................................................................................................................................................... 15 SET HIGH END .................................................................................................................................................... 15 SET LOW END WITH A VACUUM SYSTEM ................................................................................................... 15 SET LOW END WITH A REFERENCE TUBE ................................................................................................... 16 SET RELAY TRIGGER POINTS ......................................................................................................................... 16 LINEAR OUTPUT CALIBRATION .................................................................................................................... 17 ANALOG OUTPUT INTERPRETTION.............................................................................................................. 17 NON-LINEAR ANALOG OUTPUT INTERPRETATION ................................................................................. 17 LINEAR ANALOG OUTPUT INTERPRETATION ........................................................................................... 19 PRESSURE UNITS .............................................................................................................................................. 22 THERMAL COEFFICIENT ................................................................................................................................. 22 DIGITAL COMMUNICATIONS ......................................................................................................................... 23 COMMAND SYNTAX ........................................................................................................................................ 23 INTERROGATION COMMANDS ...................................................................................................................... 23 PARAMETER MODIFICATION COMMANDS ................................................................................................ 24 LINEAR COMMANDS ........................................................................................................................................ 24 LINEAR STATUS OUTPUT ................................................................................................................................ 25 RESET / INITIALIZE COMMANDS ................................................................................................................... 25 DEVICE STATUS ................................................................................................................................................ 25 WARRANTY AND REPAIR ....................................................................................................................................... 26 4.1. 4.2. WARRANTY REPAIR POLICY.......................................................................................................................... 26 NON-WARRANTY REPAIR POLICY................................................................................................................ 26
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1.General Information
This manual contains technical and general information relating to the installation, operation, and
calibration of Teledyne Hastings Vacuum Gauges, and Gauge Tubes.
For best performance, Hastings vacuum gauges should be operated with the appropriate Hastings
gauge tube. Attempting to use a Hastings vacuum gauge with other manufacturer’s tubes may result in
damage to both the gauge and tube.
1.1. FEATURES
The Teledyne Hastings Instrument’s Digital CVT, is a digital readout version of the successful CVTSeries “Hastings Gauge” which has generated loyal customers for over 50 years. A reputation has
been built on exceptional stability, accuracy, and reliability. This instrument has been designed for
laboratory or light industrial applications. It is not suitable for outdoor or heavy industrial areas where
spraying liquid or wash-downs may occur.
A precision A/D converter, with a microprocessor is used to measure the gauge tube’s signal output; it
converts the measurement to a pressure reading using the gauge tube’s well defined output/pressure
function, and then displays the result. A 0 – 1 volt amplified non-linear gauge tube output version
along with 0-1volt, 0-5volt, 0-10volt, 0-20mA, and 4-20mA linear gauge tube output versions are
available on the back panel. The current pressure reading can also be acquired digitally through the
standard RS232 port. The dual control points are durable 10 amp single pole double throw relays
which can be configured normally open or normally closed.
The Digital CVT Vacuum Gauge Meter is available for Teledyne Hastings Instruments most popular
gauge tube families: DV-4, DV-5, and DV-6. The DV-4 range is 0.2-20 Torr. The DV-5 range is 0.1 –
100 m Torr. The DV-6 range is 1-999 mTorr. All VT-Series Vacuum Gauges feature long life and
minimal maintenance.
These instruments utilize Teledyne Hastings rugged noble metal thermocouple gauge tubes that are
designed specifically for each range.
Tubes are matched and interchangeable without calibration adjustments. They are compensated for
temperature, rate of temperature change and are corrosion resistant.
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1.2. SPECIFICATIONS
DIGITAL CVT VACUUM METER:
ACCURACY .................................................................................. DV4, 0.02 – 20 Torr, ± (20% of Reading + 0.01 Torr)
.................................................................................................... DV5, 0.1 – 100 mTorr, ± (20% of reading + 0.2 mTorr)
.................................................................................................. DV6, 0.001 – 1.0 Torr, ± (15% of Reading + 0.001 Torr)
INPUT POWER ......................................................................................................................... 90-250 volts AC, 5 Watts
Optionally 24 VDC, 5 Watts
CABLES (Approx.) ................................................................................. 6-ft. power cable and 8-ft. sensor cable included
PRESSURE UNITS .............................................................................. Torr/DV-4, mTorr/DV-5, m Torr/DV-6 standard
....................................................................................................................................................... Optionally mbar, Pascal
WEIGHT (Approx.) ..................................................................................................................................... 0.7 lb (0.3 kg)
OPERATING TEMPERATURE RANGE ................................................................................................. -20OC to 70OC
RELAYS.........................................................................................................Max Switching Voltage 250 VAC, 100 VDC
....................................................................................................... Max Switching Current 10 Amps (AC), 5 Amps (DC)
..................................................................................................................................... Min DC switching 5 VDC/100 mA
NON-LINEAR ANALOG OUTPUT................................................................................................................... 0-1 VDC
LINEAR ANALOG OUTPUT ....................................................................... 0-1, 0-5, 0-10, VDC and 0-20mA, 4-20mA
DIGITAL OUTPUT ..................................................................... RS232 (9600 / 19.2k baud) (6 pin modular connector)
AC TUBE DRIVE ........................................................................................ 0.3 – 0.4 VAC, true RMS, 1 kHz square wave
(Compatible with DV-4, DV-5, and DV-6 tubes)
TUBE SIGNAL ............................................................ 0 – 10 mVDC, (compatible with DV-4, DV-5, and DV-6 tubes)
AC CONNECTION ............................................................................................................................................. IEC-320
ANALOG OUT, TUBE DRIVE, TUBE INPUT, RELAY CONNECTIONS, 24 VDC ..................12 pin terminal block
SERIAL PORT ............................................................................................................................ 6 pin modular connector
CE STANDARD COMPLIANCE
Test
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Standard
SAFETY
EN61010
EMC/EMI Family
EN61326
CONDUCTED/RADIATED
EN55011
ESD
EN61000-4-2
RF
EN61000-4-3
FAST TRANSIENTS
EN61000-4-4
SURGE
EN61000-4-5
CONDUCTED IMMUNITY
EN61000-4-6
VOLTAGE DIPS
EN61000-4-11
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1.3. SAFETY
The following symbols and terms may be found on THI products and/or in THI manuals and indicate
important information.
When found on the device, this symbol indicates that the operator should refer to the manual for
important instructions on the proper use of this device. When found in a manual, this symbol
indicates that the reader should understand the implications contained in the text before
operating the device.
The WARNING label indicates important information that should be heeded for safe and proper
performance of the device.
The label, CAUTION, is used to indicate that the damage to the power supply or equipment connected
to it could occur if directions are not followed. Warranty could be invalidated if the instructions in this
manual are not followed.
1.4. ACCESSORIES
1.4.1.
INSTALLATION ACCESSORIES
Teledyne Hastings Instruments offers a complete line of system attachments that permit easy
maintenance for contaminated operations. Gauge tubes are offered with various system fittings to
match almost any system requirement. Additionally, Teledyne Hastings’ complete line of quick
disconnect attachments allows customers to install these special fittings and easily replace sensors
without vacuum sealant or Teflon® tape. For particularly dirty systems, Teledyne Hastings offers a
particle dropout trap containing a series of nine separate baffles which prevent solid contaminants
from having a direct path to the sensor’s thermopile.
1.4.2.
CALIBRATION REFERENCE TUBES
Teledyne Hastings Instruments Reference Tubes employ the same Hastings metal thermopiles used
in all Teledyne Hastings Vacuum Gauge Tubes. The thermopile is sealed in a glass capsule that has
been evacuated, baked, out gassed, and then aged to ensure long-term stability. The sealed capsule
is then housed in a protective metal shell to provide a rugged, trouble-free assembly.
Once assembled, the reference gauge tube is accurately calibrated to precisely simulate a gauge tube
at a given operating pressure. It provides quick and easy instrument re-calibration by merely plugging
the instrument and adjusting the zero potentiometer until the display reads the exact pressure noted
on the reference tube.
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Vacuum Gauge Tubes and Cables
Vacuum Gauge Tubes 20Torr Range
Stock #
Model #
Description
55-19
DV-4D
20 T Vac Gauge Tube (Purple Base)
55-19R
DV-4R
20 T Vac Gauge Tube/Rugged
55-258
DV-4D-KF-16
20 T Vac Gauge Tube/KF-16
55-266
DV-4D-KF-25
20 T Vac Gauge Tube/KF-25
TM
TM
TM
55-227
DV-4D-VCR
20 T Vac Gauge Tube/VCR
55-69
DV-34
20 T Vac Gauge Tube/316SS
55-101
DB-16D
Ref Tube (DV-4D) for VT-4 Calibration
Vacuum Gauge Tubes 100 mTorr Range
55-19
DV-5M
1/8” NPT (Red Base)
55-230
DV-5M -VCR
VCR
55-103
DB-18
Ref Tube (DV-5M) for VT-5 calibration
TM
Vacuum Gauge Tubes 1000 mTorr Range
55-38
DV-6M
1000 mTorr (Yellow Base)
55-38R
DV-6R
1000 mT Vac Gauge Tube/Rugged
55-38S
DV-6S
1000 mT Vac Gauge Tube/Rugged w/ protective cup
55-139
DV-20
1000 mT Vac Gauge Tube/Glass
55-251
DV-6-KF-16
1000 mT Vac Gauge Tube/KF-16
TM
55-267
DV-6-KF-25
1000 mT Vac Gauge Tube/KF-25
TM
TM
55-283
DV-6-VCR
1000 mT Vac Gauge Tube/VCR
55-38R-CF
DV-6R-CF
1000 mT Vac Gauge Tube/Mini Conflat
55-66
DV-36
1000 mT Vac Gauge Tube/316SS
55-104
DB-20
Ref Tube (DV-6) for VT-6 Calibration
TM
Digital CVT Cables
CB-DCVT-8
Cable, Digital CVT,8' (std)
CB-DCVT-25
Cable, Digital CVT,25'
CB-DCVT-50
Cable, Digital CVT,50'
CB-DCVT-100
Cable, Digital CVT,100
CB-DCVT-XXX
Cable, Digital CVT,SPCL'
Extension Cables for VT Series (DVT & DCVT)
55-3
OM-8-OFV
8 Ft Extension Cable
55-22
OM-12-OFV 12 Ft Extension Cable
65-53
OM-25-OFV 25 Ft Extension Cable
65-102 OM-50-OFV 50 Ft Extension Cable
55-142 OM-100-OFV 100 Ft Extension Cable
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2.Installation
2.1. DIGITAL CVT, OUTLINE DIMENSIONS
2.2. DIGITAL CVT, FRONT PANEL
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2.3. DIGITAL CVT, BACK PANEL
2.4. PANEL MOUNTING
Shut-off power to the panel. Install the Digital CVT through the panel cutout as shown in the illustration
below. Attach brackets to the side of the case and tighten until the front of the case is snug against the
instrument panel. Use the power cord supplied with the unit and follow local codes when connecting
power source to the unit.
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2.5. DIGITAL CVT-33D, OUTLINE DIMENSIONS
2.6. TERMINAL BLOCK
Terminal Block
Pin#
Description
1
Analog Out
2
Common
3
24 VDC
4
Tube – Green
5
Tube – White
6
Tube – Black
7
Relay1 – NC
8
Relay1 – Common
9
Relay1 – NO
10
Relay2 – NC
11
Relay2 – Common
12
Relay2 - NO
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12 11 10 9
8
7
6
5
4
3
2
1
Figure 1
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2.7. RELAY CONNECTION
There are two relays installed in the Digital CVT. Each relay can be set to trigger independently. Both
relays are setup to be de-energized at high pressure and to energize when the indicated pressure is
below the setpoint. Normally-open (NO), common and normally-closed (NC) terminals are available for
each relay on the rear terminal block. The normally-open contact for Relay1 (terminal 9) will connect to
the common terminal for Relay1 (terminal 8) when the indicated pressure is less than the setpoint. The
normally-closed contact for Relay1 (terminal 7) will be connected to the common terminal for Relay1
whenever the pressure is greater than the setpoint or when power is lost. The contacts for Relay2
operate similarly.
These connections can be used to start/stop pumps, ion gauges or to open/close system valves at
selected pressures. The specifications for the switching capability can be found in Specifications section
of this manual.
2.8. DIGITAL CONNECTION
1
6
The Digital CVT uses an RJ12 modular connector (6P6C).
See the table below for the standard pin-out:
Pin#
RS232
1
2
TX
3
Ground
4
Ground
5
RX
Figure 2
6
The pins are numbered looking into the female connector with the pins on the top from left to right. Note
that the TX pin is defined as signals being transmitted from the Digital CVT to the bus master while the
RX pin is defined as signals being received by the Digital CVT Series from the buss master.
Teledyne Hastings offers a preassembled cable that will interface between a Digital CVT and a standard
9 pin computer serial port (#CB-RS232-RJ12). If making up a cable to interface to the standard PC 9 pin
serial port use the following connections:
RJ12
NC
2
5
NC
4
NC
NC
NC
NC
D9 Female
1
2
3
4
5
6
7
8
9
The default port set-up is 19.2K baud, 8 data bits, no parity, and no flow control. If the instrument
receives a Ctrl-Z (hex 1A, decimal 26) character it will automatically set itself to the baud rate of the port.
The <ctrl-z> is entered by holding down the “Ctrl” key while pressing the “z” key when using terminal
emulator program.
2.9. ANALOG OUTPUT CONNECTION
The Digital CVT may be configured to have one of several types of analog outputs available on pins 1
and 2 of the terminal block. One type is a 0 – 1 volt signal, which is equal to an amplified tube millivolt
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signal. This signal will NOT be linearly proportional to the indicated pressure. 1 volt will correspond to a
system pressure that is less than 1 mTorr. Increasing pressure will be indicated by a decreasing
voltage. The load resistance connected to these terminals must be kept above 2 K ohms. See Section
3.11 “ANALOG OUTPUT INTERPRETATION” for more information.
The Digital CVT can also be configured for one of the following linear analog outputs: 0-1v, 0-5v, 0-10v,
0-20mA and 4-20mA. See Sections 3.6, 3.10 and 3.14.4. These voltage and current outputs will increase
linearly with increasing system pressure.
The current loop output is useful for remote applications where pickup noise could substantially affect
the stability of the voltage output or long cable runs where cable resistance would cause a voltage signal
to decay. The current loop signal replaces the voltage output on pin 1 of the terminal block. The current
loop is sourced internally and must be returned to common on pin 2 after passing through the monitoring
circuitry to complete the loop. The load must be between 0 and 1200 Ohm.
If the instrument is being powered through the 24 VDC pin on the rear terminal board instead of with AC
power, the analog output may have an offset of 63 millivolts due to the voltage drop created by the
supply current.
CURRENT LOOP WIRING
DATA
ACQUISITION
DEVICE
DCVT
1
< 1200
Ohms
2
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3.Vacuum Gauge Operation
All Teledyne Hastings gauge tubes are shipped with a protective cap or cover at the evacuation port to
reduce contamination and prevent damage to the internal thermopile elements. Once the protective cap
or cover is removed, a tube can be installed in any convenient position in the vacuum system without
adversely affecting calibration or performance. The recommended orientation is with the tube vertical and
its stem down. This will aide in preventing condensable materials from remaining in the gauge tube.
3.1. AC INPUT POWER
The Digital CVT Power Supply input is rated as consuming 0.05 Amps @ 120VAC (< 0.12 Amps
at 90 VAC).
The Digital CVT uses an IEC-320 power cable. To operate the Digital CVT, plug the power cable
into the connector located in the rear of the Digital CVT. Connect the plug of the power supply into a
single phase 90 - 250 VAC. 50/60 Hz power source
3.2. QUICK START
1. Shut-off power to the instrument panel
2. If desired, install the Digital CVT into the instrument panel as detailed in section 2.4.
3. Plug the Gauge Tube Cable into the connector on the rear panel of the Digital CVT.
4. Connect the Octal Socket cable assembly that is attached to the rear of the Digital CVT to a DV4,
DV5 or DV6 gauge tube.
5. Plug Digital CVT power cable into a 90 - 250 VAC. 50/60 Hz outlet source. Energize the
instrument panel.
6. The CPU will do a self check/initialization. The digital display should count up and stop
momentarily at FFF. (Note: If the digital display shows a "- - -", this means the instrument is out of
range or gauge tube is unplugged.)
7. The Torr and mTorr LED’s should also momentarily illuminate.
8. After the CPU is operating, and the self-check/initialization is complete, the display will indicate the
output of the DV4, DV5 or DV6 tube.
9. For a more accurate reading from the DV4, DV5 or DV6 tubes, refer to Section 3.7 and perform a
calibration of unit.
3.3. PRESSURE MEASURMENT
Connect the gauge tube cable’s octal socket onto the octal base of a gauge tube installed in vacuum
system. The gauge will display the system pressure on the Digital CVT. To check the accuracy of the
gauge, perform the required operations as specified in section 3.8.
3.4. OPERATION AND PERFORMANCE
The Digital CVT will be calibrated at the factory. Recalibration is not required. For maximum accuracy
refer to section 3.8 “CALIBRATION PROCEDURE”.
The simplest and quickest way of checking the operation and performance of a gauge and/or gauge
tube, is to keep a new, or known-good gauge tube on hand for use as a Reference.
To check operation, install both a reference vacuum gauge and unit under test gauge tubes in a common
vacuum system (locate the gauge tubes as close as possible to each other), then evacuate the system
until a stable base pressure is obtained. Alternately connect the vacuum gauge to each gauge tube and
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record its pressure readings. If the gauge tube-under-test produces a higher pressure reading than the
Reference gauge tube then a calibration shift has occurred, usually as the result of contamination
(particulate, oil, or other chemical deposits). You can try to restore calibration of the contaminated gauge
tube by cleaning it internally with an appropriate solvent such as high-purity isopropyl alcohol (flood the
interior cavity of gauge tube gently with solvent and allow it to stand and soak for about 15 to 30minutes). Drain the contaminated solvent and let gauge tube dry in ambient air until all of the cleaning
solvent has evaporated. To prevent mechanical damage to the thermopile elements, do not use forced
air to dry the gauge tube. Gauge tubes that remain out of calibration after cleaning should be replaced.
3.5. GAUGE TUBE OPERATING PRINCIPLE
Operation of the Teledyne Hastings gauge tube is based on a low voltage AC bridge that heats a noble
metal thermopile. A change in pressure in the gauge tube changes the molecular collision rate and
therefore the thermal conduction of the gas or gas mixture surrounding the thermopile. This results in a
temperature shift in the AC heated thermocouples A and B (Fig. 3). The resultant temperature shift
causes a change in the DC output from couples A and B inversely with pressure changes. When
installed, the DC thermocouple C is in series with the circuit load. Thermocouple C provides
compensation for transient changes in ambient temperature.
Figure 3
3.6. LINEAR OUTPUT SELECTION
The Digital CVT will be set for linear or non-linear analog output at the factory. The customer may
change the Digital CVT unit from its current linear or non-linear configuration by rearranging the jumper
settings of J24, located internally next to Pins 1 & 2 of the Terminal Block, to match Figure 4 for the
desired analog output.
Figure 4: J24 Jumper Arrangement / Orientation
During linear output configuration, the customer may change the output voltage to 0-10v, 0-5v, 0-1v, 020ma, or 4-20ma linear full scale. Refer to sections 3.10 “LINEAR OUTPUT CALIBRATION” and 3.14.4
“LINEAR COMMANDS” for linear output calibration and commands.
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3.7. TUBE SELECTION
The Digital CVT can be setup to operate with a Hastings DV4, DV5 or DV6 vacuum gauge tube. There is
a jumper located on the rear panel which will select the desired tube. Normally the Digital CVT will arrive
from the factory configured for the tube type specified by the customer order. However if the system
pressure range changes, and a different tube type will now be used, the tube type can be changed by
moving the jumper position. The tube calibration procedure in section 3.8 must be performed after
changing the tube type.
Note: Complete removal of the jumper will be interpreted by the internal processor as the DV4
configuration. The Digital CVT-5 instrument will always read in either DV-4 or DV-6 configuration,
therefore, no jumper arrangement is needed for the Digital CVT-5. Also, while in field, it is not possible to
change a DV-4 or DV-6 to a DV-5.
DV4
DV6
Jumper Arrangement
Figure 5: Rear Panel Jumper Arrangement
3.8. CALIBRATION PROCEDURE
3.8.1. PREPARATION
1. Plug in DV-4, DV-5 or DV-6 gauge tube. Leave tube at atmospheric pressure.
2. Plug the Digital CVT power supply into an outlet providing 90 -250 VAC, 50/60 Hz.
3. CLEAR out any previously entered calibration data.
a. Using a pointed object, such as a ballpoint pen, press and hold the “ATM” push button located on
the front panel until “CLR” appears on the digital display. The “ATM” button must be held in the
pressed position approximately 5 seconds before data is cleared and “CLR” is displayed.
4. Once “CLR” is displayed any previously entered data has been deleted.
3.8.2. SET HIGH END
NOTE: TUBE MUST BE AT ATMOSPHERE TO PROPERLY SET THE HIGH END.
A. Press “ATM” push button until “Set” appears. The high-end is now set.
3.8.3. SET LOW END WITH A VACUUM SYSTEM
NOTE: The LOW END can be adjusted by either bringing the system to a known vacuum or by using a
TELEDYNE HASTINGS REFERENCE TUBE.
A. Set system to known vacuum.
B. Turn the “VAC” pot on the front panel until the known vacuum is displayed on the digital display. (For
DV-4, DV-5, and/or DV-6 IF KNOWN VACUUM IS BELOW 1 mTorr FOR DV-4 AND DV-6 OR 0.1
mTorr FOR DV-5, SET DISPLAY TO ZERO).
C. The low end is now adjusted.
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3.8.4. SET LOW END WITH A REFERENCE TUBE
A. Connect a TELEDYNE HASTINGS reference tube.
B. Turn the “VAC” pot until the value printed on TELEDYNE HASTINGS reference tube is displayed on
digital Display.
C. THE LOW END is now adjusted.
NOTE: If re-calibration is required you must first repeat step 3.8.2.
IF SEVERAL TUBES ARE TO BE READ AND RE-CALIBRATION FOR EACH TUBE IS NOT DESIRED,
YOU MAY CLEAR THE CALIBRATION DATA (STEP 2) AND ONLY ADJUST THE LOW END SETTING
ONCE. HOWEVER A LOSS OF ACCURACY WILL BE NOTICED ON THE HIGH END.
Note: The following table specifies the TELEDYNE HASTINGS reference tube to be used in the
calibration of a gauge based upon the type of gauge tube being used.
Ref. Tube
DB-16D
DB-18
DB-20
Gauge Tube
DV-4
DV-5
DV-6
NOTE: ONCE CALIBRATION IS COMPLETE THE CALIBRATION DATA IS PERMANENTLY STORED
IN NONVOLATILE MEMORY. A LOSS OF POWER WILL NOT ERASE THE CALIBRATION DATA.
3.9. SET RELAY TRIGGER POINTS
The Digital CVT provides 2 relays for process control. Each relay has a normally-open, a common and a
normally-closed contact available through the terminal block on the rear of the instrument. The pin-out is
shown in Figure 1 of section 2.7. Each relay operates independently from each other. Each relay will be
energized whenever the pressure measured by the vacuum tube is less than the value that has been set
for each relay. Upon loss of power the Digital CVT relays will indicate a high pressure condition.
There is a small amount of hysteresis present in the relay trigger point in order to prevent excessive relay
switching if the system operating pressure is close to a setpoint. The relay will energize exactly on the
setpoint but it will de-energize ≈ 1% of reading above the setpoint.
The relays can be read or changed by locally using front panel controls or remotely through the serial
port. To view and change the set point for relay #1 using the front panel controls, press the switch next
to the SP1 designator. The display will indicate the pressure value that is currently set on the
potentiometer next to the SP1 designator (if the setpoint had been set remotely via the serial port the
display will not indicate this remotely set value and the local value will now over-ride the previous value).
While holding the switch, adjust the potentiometer knob until the desired pressure is indicated on the
display. When the switch is released, this pressure value will be stored as the setpoint for relay #1 and
the instrument will return to normal pressure indication.
Relay #2 can be set similarly using the controls next to the SP2 designator. While the instrument is in
the setpoint adjust mode it cannot monitor the pressure at the vacuum tube and relays will not be
set/reset if the pressure changes until the switch is released. The setpoints can be read and changed
remotely through the serial port. [Whenever the appropriate setpoint switch is pressed and released
the current setpoint will be changed to the value currently set by the potentiometer regardless of
the any changes made remotely.] Rotating the potentiometer while the switch is not pressed will not
affect the setpoint however the next time the switch is pressed the setpoint will change to the rotated
value.
The relay switching can be prevented by setting the setpoint above or below the pressure range of the
vacuum tube. Setting the setpoint to a negative value will keep the relay de-energized and setting the
setpoint to high value will keep the relay energized at all times.
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3.10. LINEAR OUTPUT CALIBRATION
The Digital CVT linear output voltage will be set and calibrated at the factory per the customer’s
requested configuration. However, the customer may change the output voltage to 0-1v, 0-5v, 0-10v, 020ma, or 4-20ma linear full scale.
Setup:
1. Connect the Digital CVT to HyperTerminal using the Teledyne Hastings preassembled RS232
cable that will interface between a Digital CVT and a standard 9 pin computer serial port (#CBRS232-RJ12). Refer to section 2.8 “DIGITAL CONNECTION”.
2. Ensure pins 2 & 3 of the analog output jumper J24 are as shown in Figure 4 located in section
3.6 for Linear Output.
3. Connect a multimeter to pins 1 & 2 of the Terminal Block of Figure 1 located in section 2.6
“TERMINAL BLOCK”.
Note: Step 3 will allow the user to change the desired output voltage configuration and adjust the
appropriate HyperTerminal command until the adequate full scale values have been reached.
Procedure: (Refer to section 3.14.4 “LINEAR COMMANDS”)
1. Send the command via Hyper Terminal for the desired voltage full scale range. (Ex. D1 for 1
volt Range)
2. Set the Zero value first by sending the “DAZ” command, then “DZ” command to check the
current value for zero. The user should see a value given in scientific notation.
3. Use the “DZ=” command to adjust the zero value until the multimeter displays “0.000v” for 1v,
10v, and 5v ranges, and “4mA” for 4-20ma. The zero adjustment value should be between
“32000” and “33000”.
4. Once the desired zero value is reached, use the “DZW” command to set this value.
5. Repeat procedures 1-4 to set the span value, using the respective span commands listed in
section 3.14.4 “LINEAR COMMANDS”.
Note: When adjusting the span value using the “DS=” command, the starting adjustment value should
begin around “6000-7000” for 1v range, “32000-33000” for 10v and 5v ranges, and “22000-23000” for the
0-20ma and 4-20ma range.
3.11. ANALOG OUTPUT INTERPRETTION
3.11.1. NON-LINEAR ANALOG OUTPUT INTERPRETATION
The Digital CVT has a 0 – 1 volt analog output signal available on pins 1 and 2 of the terminal block.
This signal is equal to an amplified tube millivolt signal. The following signal is NOT linearly
proportional to the indicated pressure. 1 volt will correspond to a system pressure that is less than 1
mTorr. Increasing pressure will be indicated by a decreasing voltage.
The voltage signal can be mapped to a pressure value by using the following equation.
P
a  cV  eV 2
1  bV  dV 2
Where:
Parameters
a
b
c
d
e
DV6
-1623.22
-58.0442
-11732.2
-130.397
13338.17
DV4
-5.10184
-6.91233
-4.4943
-6.30995
9.563177
DV5
-0.25948
-42.23869
-2.92598
-256.99510
3.18016
V = Voltage
P = pressure in Torr for DV4, and DV5, and in mTorr for DV6
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Analog Output vs Pressure
100
DV6
DV4
10
DV5
Pressure (Torr)
1
0.1
0.01
0.001
0.0001
0
173-012014_Digital-CVT
0.2
0.4
0.6
Voltage
0.8
1
1.2
Page 18 of 26
3.11.2. LINEAR ANALOG OUTPUT INTERPRETATION
The Linear Digital CVT provides voltage span values of 0 – 1v, 0 – 5v, 0 – 10v, 0-20ma, and 4ma 20ma. These analog output signals are available on pins 1 and 2 of the terminal block. This signal is
equal to an amplified tube millivolt signal. The following signals are linearly proportional to their
indicated voltages. Increasing pressure will be indicated by an increasing voltage.
The pressure value can be mapped to a voltage signal by using the following equation.
Where:
V = Voltage
P = pressure in Torr for DV-4, and in mTorr for DV-5, DV-6, and DV-33
Mp = Max pressure range (20 Torr, 100 mTorr, 1000 mTorr)
vsp = Voltage Span Value (example: 5 for 0-5v)
Note: The 4-20ma was calculated with the range of 0ma-16ma, and 4ma is added to the
final value in order to obtain a 4-20ma range.
DV-4 (0-20 Torr Range)
10
9
8
10 volt
Voltage
7
5 volt
6
1 volt
5
4
3
2
1
0
0
2
4
6
8
10
12
14
16
18
20
Pressure (Torr)
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DV-5 (0-100 mTorr Range)
10
9
8
10 volt
Voltage
7
5 volt
6
1 volt
5
4
3
2
1
0
0
10
20
30
40
50
60
70
80
90
100
Pressure (mTorr)
DV-6 & DV-33 (0-1000 mTorr Range)
10
9
Voltage
8
7
10 volt
6
5 volt
5
1 volt
4
3
2
1
0
0
200
400
600
800
1000
Pressure (mTorr)
The 4-20ma value can be mapped to a milliamp signal by using the following equation.
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DV-4 (4ma - 20ma & 0ma - 20ma)
20
18
16
Milli Amps
14
4ma - 20ma
0ma - 20ma
12
10
8
6
4
2
0
0
4
8
12
16
20
Pressure (Torr)
DV-5 (4ma - 20ma & 0ma - 20ma)
20
18
Milli Amps
16
14
4ma - 20ma
0ma - 20ma
12
10
8
6
4
2
0
0
10
20
30
40
50
60
70
80
90
100
900
1000
Pressure (mTorr)
DV-6 & DV-33 (4ma - 20ma & 0ma - 20ma)
20
18
Milli Amps
16
14
4ma - 20ma
12
0ma - 20ma
10
8
6
4
2
0
0
100
200
300
400
500
600
700
800
Pressure (mTorr)
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3.12. PRESSURE UNITS
The Digital CVT will arrive configured per customer order for one of these 3 possible pressure unit
settings: Torr, mbar, Pascal. When setup at the factory the front panel overlay will indicate the proper
units. However it can be changed in the field with a digital command over the serial interface. If changed
in the field, the units shown on the overlay will not match the units of the displayed pressure. The
pressure indication received serially will always report in the base of the selected units using scientific
notation.
Since the DV4, DV5, and DV6 tube have a different pressure range, a different multiplier of each
pressure unit is required to be able to display both tube types on the same 3 digit display. The top LED
will light when in the DV4 mode and it will indicate that the larger version of the base pressure unit is
active. When a DV-5 or DV-6 tube is being used, the bottom LED will light and indicate that the smaller
version of the pressure unit is presently active as shown in the table below.
Instrument
Pressure Units
Base Multiplier
Torr
1
hPascal
100
mbar
1
Torr
0.001
hPascal
0.1
mbar
0.001
Torr
0.001
hPascal
0.1
mbar
0.001
DV4
DV5
DV6
RS232
U1
U2
U3
To convert the value given by the LED display to the given base unit, multiply the displayed value by the
appropriate base multiplier. As an example, if a DCVT-6 version of a Digital CVT is configured for Pascal
and is displaying 543 then the current pressure is 543 x 0.1 = 54.3 Pascal. In this case the serial port
would report the pressure as “Pa: 5.43000e+1 Pascal<CR>”.
If a DCVT-6 is configured for mbar and is displaying 543, the current pressure is 543 x 0.001 = 0.543
mbar. In this case, the serial port would report the pressure as “Pa: 5.43000e-1 mbar<CR>”. To convert
mbar to bar multiply by 0.001. (Ex. 0.543 x 0.001 = 0.000543 bar)
3.13. THERMAL COEFFICIENT
The Digital CVT generates an AC heating voltage using an internal transformer. This heating voltage is
supplied to the vacuum tube to warm up the thermocouples in order to measure the pressure. As the
ambient temperature increases or decreases, the internal resistance of the copper winding in the
transformer also changes. This resistance change will change the AC heating voltage that the vacuum
tube receives. It will also change the pressure reading slightly. The typical rate of change for both tube
types is given below:
DV6
0.06 mTorr/°C + 0.09% of reading/°C
DV4
0.9 mTorr/°C + 0.03% of reading/°C
Increasing the temperature will cause the pressure readings to increase, while decreasing temperature
will cause the pressure readings to decrease. The instruments are initially adjusted at an ambient
temperature of approximately 22°C. This effect can be corrected by adjusting the low pressure reading
173-012014_Digital-CVT
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at the operating ambient temperature. The specified rate of change does not include any changes due to
thermal effects on the vacuum tube or actual changes in pressure that occur in a vacuum system during
temperature excursions.
3.14. DIGITAL COMMUNICATIONS
Communication with the serial interface of the Digital CVT is via an ASCII data string. The command
message consists only of a command string and the terminator. If all components of the ASCII data
string are valid, the command will be accepted and executed.
3.14.1. COMMAND SYNTAX
In the following examples of syntax codes, the special characters are explained:
The characters in square brackets [ ] represent a command string, either upper or lower case command
characters accepted. All characters must follow each other in the string with no spaces or other
characters.
The characters within wavy brackets { } contain choices for the appropriate command.
The characters within the symbols < > are the common abbreviations for the one digit ASCII control
codes which they represent, (e.g. <CR> represents carriage return).
When entering more than one command in the same data string, they must be separated by a comma.
All command strings must be followed by the terminator character (carriage return <CR>, also known as
ENTER).
When a lower case character is present in an example it represents an option.
Character
Description
Valid Inputs:
m
Most Significant Digit of Mantissa
1-9
d
Decimal Digit
0-9
e
Exponent
0-5
<CR>
Command Terminator (carriage return)
N/A
3.14.2. INTERROGATION COMMANDS
Command Description
Format
Sample Response
Get Current Pressure
P<CR>
Pa: 1.23456e+0 Torr<CR>
Get Output Voltage
U<CR>
Vavg: 1.23456e-1 Volts<CR>
Get Relay #1 Setpoint
S1<CR>
SP1: 1.0240e-2 mbar<CR>
Get Relay #1 Setpoint
S2<CR>
SP2: 4.3639e-2 Pascal<CR>
Get Relay Status
RS<CR>
0,R1:OFF,R2:OFF<CR>
Get Device ID
ID<CR>
Digital CVT<CR>
Get Sensor Type
ST<CR>
DV-6<CR>
Get Software Version #
V<CR>
Digital CVT 1.1.0 <CR>
Get Serial Number
SN<CR>
1023400012<CR>
Get User Data
UD<CR>
Text String<CR>
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3.14.3. PARAMETER MODIFICATION COMMANDS
Command Description
Format
Valid Range:
Set unit to Torr
U1<CR>
All subsequent values in Torr
Set unit to Pascal
U2<CR>
All subsequent values in Pascal
Set unit to Mbar
U3<CR>
All subsequent values in mbar
Modify User Data
UD=Text String<CR>
10 character maximum
Modify Relay#1 Setpoint
S1= {m.dd} E {+e} <CR>
1.00000e-9 to 9.99999e+9
Modify Relay#2 Setpoint
S2 {m.dd} E {-e} <CR>
1.00000e-9 to 9.99999e+9
Notes:
The “User Data” is a 10 digit text area reserved for the use by the customer for identification purposes.
For example, “User Data” could be set to reply “Foreline #1”.
The setpoints may also be entered as a decimal number, e.g. [S1=0.760<CR>] will be same as entering
[H=7.60E-1<CR>].
When inputting setpoint data, it should be entered in the same Units of Pressure as the presently
selected Units of Measurement (i.e. Torr, mbar or Pascal). The data is only checked to be a valid number
with a one digit exponent before being accepted. There are no limit checks on the data; the user is free to
choose any value appropriate to his use of the instrument.
If the command syntax is not met or if the number is out or range, the Digital CVT will respond with the
ASCII codes for <bell>?<CR>, and the command will be ignored.
3.14.4. LINEAR COMMANDS
After switching to linear output operation, some instrument calibration may be required. Refer to section
3.10 “LINEAR OUTPUT CALIBRATION” for calibration setup and procedure.
Command Description
Command
Notes:
1 Volt Range
D1
Selects 1 Volt DAC Range
5 Volt Range
D5
Selects +/-5 Volt DAC Range
10 Volt Range
D10
Selects +/-10 Volt DAC Range
0-20 mA Range
D0
Selects 0-20 mA DAC Range
4-20 mA Range
D4
Selects 4-20 mA DAC Range
Read Zero Value
DZ
Read the DAC Zero Value
Set Zero Value
DZ=
Set the DAC Zero Value
Store Zero Value
DZW
Store the DAC Zero Value
Read Span Value
DS
Read the DAC Span Value
Set Span Value
DS=
Set the DAC Span Value
Store Span Value
DSW
Store the DAC Span Value
Output Zero Value to DAC
DAZ
Output Zero Value to DAC
Output Span Value to DAC
DAS
Output Span Value to DAC
Output Pressure Value to DAC
DAP
Output Pressure Value to DAC
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3.14.5. LINEAR STATUS OUTPUT
The Digital CVT will arrive configured per customer order for one of the 5 possible linear output ranges:
0-1v, 0-5v, 0-10v, 0-20ma, or 4-20ma. The “ST” command provides the customer the ability to view the
currently selected DV-Tube and linear output range. The following table provides the RS232
communication output of each DV-Tube and linear output.
Refer to section 3.14.2 “INTEROGATION COMMANDS” for general “ST” command description, format,
and sample response.
Instrument
Linear Output
“ST” Command Response
0-1Volt
DV-x 0-1Volt
0-5Volt
DV-x 0-5Volt
0-10Volt
DV-x 0-10Volt
0-20ma
DV-x 0-20 mA
4-20ma
DV-x 4-20 mA
DV-x
Where x = 4, 5, 6 or 33 depending upon DV-Tube being used.
Note: When the Digital CVT unit is set to non-linear configuration per Figure 4 in section 3.6 “LINEAR
OUTPUT SELECTION”, only the DV-Tube type (DV-x) of the “ST” command response is valid.
3.14.6. RESET / INITIALIZE COMMANDS
Command Description
Format
Notes:
Software Reset
/<CR>
Reset instrument
Autobaud
<ctrl-z><CR>
Match baud rate currently in use
The <ctrl-z> is entered by holding down the “Ctrl” key while pressing the “z” key when using terminal
emulator program. This character has an ASCII code of 26 (decimal) and 1A (hexadecimal).
3.14.7. DEVICE STATUS
When requested to transmit the relay status, the Digital CVT responds with a 3 part text string which is
explained in the following:
0, R1: OFF, R2: OFF
1st part (before 1st comma) binary representation of the state of both relays
0 = 0 + 0 = both relays off
1 = 0 + 1 = relay 2 – off, relay 1 – on
2 = 2 + 0 = relay 2 – on, relay 1 – off
3 = 2 + 1 = both relays on
2nd part and 3rd part describe textually the status of each relay.
R1: OFF = Relay 1 is de-energized; pressure is above the setpoint for Relay1.
R1: ON = Relay 1 is energized; pressure is below the setpoint for Relay1.
R2: OFF = Relay 2 is de-energized; pressure is above the setpoint for Relay2.
R2: ON = Relay 2 is energized; pressure is below the setpoint for Relay2.
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4.Warranty and Repair
4.1. WARRANTY REPAIR POLICY
Teledyne Hastings Instruments warrants this product for a period of one year from the date of shipment
to be free from defects in material and workmanship. This warranty does not apply to defects or failures
resulting from unauthorized modification, misuse or mishandling of the product. This warranty does not
apply to batteries or other expendable parts, nor to damage caused by leaking batteries or any similar
occurrence. This warranty does not apply to any instrument which has had a tamper seal removed or
broken.
This warranty is in lieu of all other warranties, expressed or implied, including any implied warranty as to
fitness for a particular use. Teledyne Hastings Instruments shall not be liable for any indirect or
consequential damages.
Teledyne Hastings Instruments, will, at its option, repair, replace or refund the selling price of the product
if Teledyne Hastings Instruments determines, in good faith, that it is defective in materials or
workmanship during the warranty period. Defective instruments should be returned to Teledyne Hastings
Instruments, shipment prepaid, together with a written statement of the problem and a Return Material
Authorization (RMA) number. Please consult the factory for your RMA number before returning any
product for repair. Collect freight will not be accepted.
4.2. NON-WARRANTY REPAIR POLICY
Any product returned for a non-warranty repair must be accompanied by a purchase order, RMA form
and a written description of the problem with the instrument. If the repair cost is higher, you will be
contacted for authorization before we proceed with any repairs. If you then choose not to have the
product repaired, a minimum will be charged to cover the processing and inspection. Please consult the
factory for your RMA number before returning any product repair.
TELEDYNE HASTINGS INSTRUMENTS
804 NEWCOMBE AVENUE
HAMPTON, VIRGINIA 23669 U.S.A.
ATTENTION: REPAIR DEPARTMENT
TELEPHONE
(757) 723-6531
1-800-950-2468
FAX
(757) 723-3925
E MAIL
mailto:hastings_instruments@teledyne.com
INTERNET ADDRESS
http://www.teledyne-hi.com/
Repair Forms may be obtained from the “Information Request” section of the Teledyne Hastings
Instruments web site.
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