167A Readout/Set Point Module

167A Readout/Set Point Module
114792-P1
Rev C, 9/95
Instruction Manual
MKS Type 167A
Single Channel
Flow Readout
Six Shattuck Road
Andover, MA 01810-2449
(800) 227-8766 or (978) 975-2350
Fax: (978) 975-0093
E-mail:[email protected]
Web site: http://www.mksinst.com
WARRANTY
167A Equiptment
MKS Instruments, Inc. (MKS) warrants that the
equipment described in the face of this warranty (the
"equipment") manufactured by MKS shall be free from
defects in materials and workmanship for a period of
one year from date of shipment. For the period
commencing with the date of shipment of this equipment
and ending one year later, MKS will, at its option,
either repair or replace any part which is defective in
materials or workmanship without charge to the
purchaser. The foregoing shall constitute the exclusive
and sole remedy of the purchaser for any breach of
MKS of this warranty.
The purchaser, before returning any equipment covered
by this warranty, which is asserted to be defective by the
purchaser, shall make specific written arrangements with
respect to the responsibility for shipping the equipment
and handling any other incidental charges with the MKS
sales representative or distributor from which the
equipment was purchased or, in the case of a direct
purchase from MKS, with the MKS home office in
Andover, Massachusetts, U.S.A.
This warranty does not apply to any equipment which has
not been used in accordance with the specifications
recommended by MKS for the proper and normal use of
the equipment. MKS shall not be liable under any
circumstances for consequential or incidental damages in
connection with, or arising out of, the sale, performance,
or use of the equipment covered by this warranty.
THIS WARRANTY IS IN LIEU OF ALL OTHER
WARRANTIES BY MKS, EXPRESSED OR IMPLIED,
INCLUDING THE IMPLIED WARRANTY OF MERCHANTABILITY, THE IMPLIED WARRANTY OF FITNESS
FOR A PARTICULAR PURPOSE, AND ANY WARRANTY
AGAINST INFRINGEMENT OF ANY PATENT.
5-96
114792-P1
114792-P1
REV C, 9/95
MKS Type 167A
Single Channel
Flow Readout
TYPE 167 FLOW READOUT
Gauge
Factor
Zero
Open
Flow
Close
Set Pt.
Set Point
Copyright © 1995 by MKS Instruments, Inc.
All rights reserved. No part of this work may be reproduced or transmitted in any form or by
any means, electronic or mechanical, including photocopying and recording, or by any
information storage or retrieval system, except as may be expressly permitted in writing by MKS
Instruments, Inc.
Table of Contents
Table of Contents
Safety Procedures and Precautions.......................................................................................... 1
Chapter One: General Information......................................................................................... 3
Introduction ............................................................................................................... 3
Customer Support ...................................................................................................... 4
How This Manual is Organized.................................................................................. 4
Instrument Overview ................................................................................................. 5
Dimensions ................................................................................................... 5
The Front Panel............................................................................................. 7
The Back Panel ............................................................................................. 9
Chapter Two: Installation and Operation ............................................................................... 13
How To Unpack the Type 167 Readout...................................................................... 13
Unpacking Checklist ..................................................................................... 13
Product Location and Requirements........................................................................... 14
Setup ......................................................................................................................... 15
How To Adjust the Gauge Factor............................................................................... 17
How To Adjust the Set Point ..................................................................................... 19
To Adjust the Set Point by Adjusting the Flow Rate in the Display ............... 19
To Adjust the Set Point by Adjusting the Set Point Pot ................................. 20
How To Command the MFC Operation ..................................................................... 22
To command an MFC to go to full open........................................................ 22
To command an MFC to go to full close ....................................................... 22
To command an MFC to operate according to the set point ........................... 22
How To Zero the MFC .............................................................................................. 23
How To Adjust the Decimal Point ............................................................................. 24
Chapter Three: Gas Correction Factor.................................................................................... 25
General ...................................................................................................................... 25
How To Determine What Range MFC to Use ............................................................ 26
Appendix A: Product Specifications ...................................................................................... 27
Specifications ............................................................................................................ 27
iii
Table of Contents
Appendix B: Gas Correction Factors......................................................................................29
Index ......................................................................................................................................33
iv
List of Figures
List of Tables
List of Figures
Figure 1: The Type 167 Readout, MFC, and Power Supply ................................................... 3
Figure 2: Front View Dimensions.......................................................................................... 5
Figure 3: Side View Dimensions ........................................................................................... 5
Figure 4: Back View Dimensions .......................................................................................... 6
Figure 5: Five Unit Rack Dimensions.................................................................................... 6
Figure 6: Panel Cutout Dimensions ....................................................................................... 6
Figure 7: Front Panel of the Type 167 Readout...................................................................... 7
Figure 8: Back Panel of the Type 167 Readout ...................................................................... 9
Figure 9: Piggyback Power Connection of Several 167 Readouts .......................................... 15
Figure 10: How to Wire the Terminal Block Connectors ....................................................... 16
Figure 11: The Set Point Pot ................................................................................................. 20
List of Tables
Table 1: Back Panel Type “D” Connector Pinout......................................................................10
Table 2: Back Panel Terminal Block Connector Pinout ............................................................11
Table 3: Gauge Factors for a Range of MFCs ...........................................................................17
v
List of Figures
List of Tables
vi
Safety Procedures and Precautions
Introduction
Safety Procedures and Precautions
DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT
Do not install substitute parts or perform any unauthorized modification to the instrument.
Return the instrument to an MKS Calibration and Service Center for service and repair to ensure
that all safety features are maintained.
SERVICE BY QUALIFIED PERSONNEL ONLY
Operating personnel must not remove instrument covers. Component replacement and internal
adjustments must be made by qualified service personnel only. DO NOT replace components
with the power cable connected.
Definitions of WARNING, CAUTION, and NOTE messages used throughout the manual.
Warning
The WARNING sign denotes a hazard. It calls attention to a
procedure, practice, condition, or the like, which, if not
correctly performed or adhered to, could result in injury to
personnel.
Caution
The CAUTION sign denotes a hazard. It calls attention to an
operating procedure, practice, or the like, which, if not correctly
performed or adhered to, could result in damage to or destruction of
all or part of the product.
Note
The NOTE sign denotes important information. It calls attention to a
procedure, practice, condition, or the like, which is essential to highlight.
1
Introduction
Safety Procedures and Precautions
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2
Chapter One: General Information
Introduction
Chapter One: General Information
Introduction
The Type 167A Single Channel Flow Readout is designed to provide complete display and set
point control of any MKS mass flow controller (MFC), via front panel controls. Direct display
in standard mass flow units (sccm, slm) is easily accomplished by the proper setting of the front
panel precision scaling potentiometer (labeled Gauge Factor). This one-time setting scales the
display for the desired process gas, as well as for the appropriate MFC Full Scale range.
The three position Open/Close/Flow switch on the front panel is used to operate an MFC
according to a set point, or to send a digital low to fully open or fully close the MFC. In most
cases, the fully closed position can be used to zero the MFC. A zero pot is conveniently located
on the front panel for fine zero adjust of the MFC.
The Type 167 readout is used in conjunction with a single MFC and a ± 15 VDC, ±5% power
supply. An optional 19 inch rack, and an optional rack with five 167 readouts installed, are
available.
Cables are available to connect
the Type 167 Readout to any
MKS Mass Flow Controller
± 15 VDC ±5%
Power Supply
Figure 1: The Type 167 Readout, MFC, and Power Supply
3
Customer Support
Chapter One: General Information
Customer Support
Standard maintenance and repair services are available at all of our regional MKS Calibration
and Service Centers in North America, Europe, Israel, Japan, Korea, and Taiwan. In addition,
MKS accepts the instruments of other manufacturers for recalibration using the Primary and
Transfer Standard calibration equipment located at all of our regional service centers. Should
any difficulties arise in the use of your Type 167 instrument, or to obtain information about
companion products MKS offers, contact any authorized MKS Calibration and Service Center.
If it is necessary to return the instrument to MKS, please obtain an ERA Number (Equipment
Return Authorization Number) from the MKS Calibration and Service Center before shipping.
The ERA Number expedites handling and ensures proper servicing of your instrument.
Please refer to the inside of the back cover of this manual for a list of MKS Calibration and
Service Centers.
Warning
All returns to MKS Instruments must be free of harmful,
radioactive, corrosive, or toxic materials.
How This Manual is Organized
This manual is designed to provide instructions on how to set up and install a Type 167 unit.
Before installing your Type 167 unit in a system and/or operating it, carefully read and
familiarize yourself with all precautionary notes in the Safety Messages and Procedures
section at the front of this manual. In addition, observe and obey all WARNING and
CAUTION notes provided throughout the manual.
Chapter One: General Information, (this chapter) introduces the product and describes the
organization of the manual.
Chapter Two: Installation and Operation, explains environmental requirements and practical
considerations to take into account when selecting the proper setting for the readout.
Chapter Three: Gas Correction Factor, describes, in a general way, how the readout operates in
a gas flow system. This chapter also provides information on how to use a Gas Correction Factor
when interpreting the output signal for a gas other than the calibration gas.
Appendix A: Product Specifications, lists the specifications of the instrument.
Appendix B: Gas Correction Factors, provides a table listing the gas correction factors for the
most commonly used gases.
4
Chapter One: General Information
Instrument Overview
Instrument Overview
Dimensions
2.83 in. SQ
(71.88 mm)
Figure 2: Front View Dimensions
Note: The mounting clips are only
added when the Type 167 unit is
mounted in a panel cutout.
1.10 in.
(27.94 mm)
0.185 in.
(4.7 mm)
2.21 in.
(56.13 mm)
Figure 3: Side View Dimensions
5
Instrument Overview
Chapter One: General Information
Decimal Point
J1
J2
2.6 in. SQ
(66.00 mm)
Figure 4: Back View Dimensions
TYPE 167 FLOW READOUT
3.400 in.
(86.36 mm)
Gauge
Factor
Zero
Open
TYPE 167 FLOW READOUT
Set Point
Close
Gauge
Factor
Zero
Open
Flow
TYPE 167 FLOW READOUT
Set Point
Set Pt.
Close
Gauge
Factor
Zero
Set Point
Open
Flow
TYPE 167 FLOW READOUT
Set Pt.
Close
Gauge
Factor
Zero
Set Point
Open
Flow
TYPE 167 FLOW READOUT
Set Pt.
Close
Gauge
Factor
Zero
Open
Flow
Flow
Set Pt.
Close
Set Pt.
19.00 in.
(482.6 mm)
Figure 5: Five Unit Rack Dimensions
+0.000
- 0.015
2.66 in. SQ
(67.56 mm)
Figure 6: Panel Cutout Dimensions
6
Set Point
3.000 in.
(76.20 mm)
Chapter One: General Information
Instrument Overview
The Front Panel
Flow Monitor Readout
Gauge Factor Pot
Zero Pot
Set Point Pot
Open/Close/Flow
Switch
Gauge Factor/Flow Set Pt. Switch
Figure 7: Front Panel of the Type 167 Readout
Flow Monitor Readout
The flow monitor readout is a red, 0.56”, LED display. It has a 3½ digit DPM (Digit Panel
Meter) which can display ± 1999 Full Scale. By adjusting the Gauge Factor, this display can
show the gas-corrected flow in sccm or slm.
Zero Pot
The zero pot on the front panel of the 167 unit is used for fine zero adjustment of the MFC.
Major zero adjustment must be done at the MFC.
Gauge Factor Pot
This pot is used for analog scaling of the 167 readout for different types of gases, different MFC
Full Scale values, and units of sccm or slm. To enable this pot, the Gauge Factor/Flow/Set Pt.
switch must be held in the Gauge Factor position while adjusting the pot with a small flat edge
screwdriver.
7
Instrument Overview
Chapter One: General Information
Set Point Pot
The Set Point Pot is a precision 10-turn potentiometer used to adjust the set point voltage. The
Set Point Pot is adjusted to a percent of the mass flow controllers’ Full Scale times ten (%MFC
F.S. x 10), thereby adjusting the set point voltage. The 167 readout controls according to this set
point when the Gauge Factor/Flow/Set Pt. switch is in the FLOW position (flow mode), and
displays the flow in engineering units (sccm or slm).
Open/Close/Flow Switch
Depending upon the switch position, the 167 readout causes the MFC to completely open (Open
position), completely close (Close position), or vary its position according to the set point (Flow
position).
•
When placed in the Open position, the 167 readout sends a digital low (connector J1,
pin 4) to the MFC, causing the valve to go to full open. This TTL signal overrides the
set point signal.
•
When placed in the Close position, the 167 readout sends a digital low (connector J1,
pin 3) to the MFC, causing the valve to go to full close. This TTL signal overrides the
set point signal.
•
When in the Flow position, the 167 readout sends a set point voltage to the MFC.
Gauge Factor/Flow/Set Pt. Switch
This three position centering switch allows adjustment of the gas gauge factor or the control set
point, and allows flow control of an MFC. The centering feature of the switch causes the switch
to return to its center (Flow) position when it is released.
•
When placed in the Gauge Factor position, the Gauge Factor can be set with the Gauge
Factor pot. Adjustment of the pot configures the 167 readout to display the flow in
specific engineering units. Refer to How To Adjust the Gauge Factor, on page 17, for an
explanation of how to determine the correct Gauge Factor setting for different gases and
different MFC Full Scale values.
•
When placed in the Set Pt. position, the current set point is displayed and can be adjusted
by using the Set Point pot.
•
When placed in the Flow position, the MFC is allowed to follow the set point voltage
from the Type 167 unit.
8
Chapter One: General Information
Instrument Overview
The Back Panel
Decimal Point
Selector
Figure 8: Back Panel of the Type 167 Readout
The back panel of the 167 readout has a decimal point selector, a 15-pin Type “D” connector (J1)
for interfacing with an MFC, and a four position terminal block (J2) for input of ±15 VDC to
power the 167 readout, and an MFC.
Decimal Point Selector
This selector is used to set the appropriate decimal point in the front panel digital display.
Note
The placement of the decimal is for your convenience — it does not
affect the signal output from the 167 readout to an MFC.
When setting the Gauge Factor, it is best to utilize all of the digits in the LED display. This
maximizes the resolution of the readout and thus the accuracy of the reading.
For example, if a Gauge Factor of 200 is desired, adjust the Gauge Factor pot so that 1999 is
shown in the display (it is not possible to display 200.0). For your convenience, the decimal may
be placed between the last two digits so that 199.9 shows in the display (199.9 is the closest to
200.0 that the LED display can show).
It is also possible to set the decimal so that 1.999 or 19.99 or 1999. is shown in the
display. Regardless of where the decimal is, the 167 readout sends out the same signal. Since a
display of 199.9 is the closest to the desired display of 200.0, it would be the best choice.
9
Instrument Overview
Chapter One: General Information
J1 (15 pin, Type “D” Connector)
Table 1 lists the pinout of the J1 connector.
Back Panel Type “D” Connector Pinout
Pin
Assignment
1
No Connection
2
Flow In - MFC output is input here
3
CLOSE
4
OPEN
5
Power Ground
6
- 15 VDC
7
+ 15 VDC
8
Set Point Voltage Output to the MFC
9
5.000 VDC Reference Test Point (1 K ohm output impedance)
10
Flow Out - A 0 to 5 Volt zero-corrected output sent to some
MFCs. For use with the MFC set point circuitry to ensure that
the actual flow matches set point.
This signal is used on all MKS MFCs.
11
Analog Return
12
Analog Return
13
No Connection
14
No Connection
15
Chassis Common
Table 1: Back Panel Type “D” Connector Pinout
Note
1. The overline on the OPEN and CLOSE inputs indicate that the
line must be pulled low to activate the function.
2. Cable CB147-1 must be used to allow connection to the OPEN and
CLOSE inputs.
3. A “No Connection” pin assignment indicates that the pin has no
internal connection.
10
Chapter One: General Information
Instrument Overview
J2 (4 Position Terminal Block)
The J2 connector is located on the back panel of the readout.
Back Panel Terminal Block Connector Pinout
Pin
Function
1
+ 15 VDC to power the 167 unit and the MFC
2
- 15 VDC to power the 167 unit and the MFC
3
Power Ground
4
Chassis Ground
Table 2: Back Panel Terminal Block Connector Pinout
11
Instrument Overview
Chapter One: General Information
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12
Chapter Two: Installation and Operation
How To Unpack the Type 167 Readout
Chapter Two: Installation and Operation
How To Unpack the Type 167 Readout
MKS has carefully packed the Type 167 Single Channel Flow Readout so that it will reach you
in perfect operating order. Upon receiving the unit, however, you should check for defects,
cracks, broken connectors, etc., to be certain that damage has not occurred during shipment.
Note
Do not discard any packing materials until you have completed your
inspection and are sure the unit arrived safely.
If you find any damage, notify your carrier and MKS immediately. If it is necessary to return the
unit to MKS, obtain an ERA Number (Equipment Return Authorization Number) from the MKS
Service Center before shipping. Please refer to the inside of the back cover of this manual for a
list of MKS Calibration and Service Centers.
Unpacking Checklist
Standard Equipment:
•
Type 167 Unit
•
Type 167 Instruction Manual (this book)
Optional Equipment:
•
Electrical Connector Accessories Kit - 167A-K1 (contains mating connectors for the J1
and J2 connectors)
•
The entire line of MKS mass flow controllers excluding the 4 to 20 mA Types 1749 and
1759
For more detailed information, contact MKS Instruments, Inc. (offices and telephone
numbers are supplied on the inside back cover of this manual).
•
19” rack with 5 Type 167 readouts installed (MKS p/n 114783-G1)
•
19” rack designed to accept five Type 167 readouts (MKS p/n 114781-P1)
•
Mounting panels
•
260 PS-1 and 260 PS-3 power supplies
13
Product Location and Requirements
Chapter Two: Installation and Operation
Product Location and Requirements
•
Operating ambient temperature must be in the range of 15° to 40° C (59° to 104° F)
•
Input Power requirements are ± 15 VDC ± 5%, @ 30 mA (the 30 mA does not include
the MFC)
Refer to the MFC instruction manual for additional current required to operate the MFC.
14
Chapter Two: Installation and Operation
Setup
Setup
•
The 167 readout should be mounted in such a manner as to provide adequate air
circulation around the unit
•
The Type 167 Readout can be mounted in a panel cutout, or in an optional 19” rack
(holds up to 5 Type 167 readouts)
The dimensions for a panel cutout are 2.67 sq. in. + 000, - 0.15 (67.82 sq. mm). The
dimensions of the optional 19” rack are given in Figure 5, page 6.
•
If more than one 167 readout is being used, they can be powered through piggyback
connections
Decimal Point
Decimal Point
J1
Decimal Point
J1
J2
Decimal Point
J1
J2
J2
Decimal Point
J1
J2
J1
J2
Power
Supply
Figure 9: Piggyback Power Connection of Several 167 Readouts
Note
The type of power supply necessary, and the number of 167 units that can
be piggybacked together, depends upon the amount of current required by
the MFCs.
Wire the piggyback connections as shown in Figure 10, page 16.
15
Setup
Chapter Two: Installation and Operation
Caution
CHASSIS
GND
1
- 15 v
4
+ 15 v
CHASSIS
GND
+ 15 v
- 15 v
1
Be sure to wire the terminal block connectors as shown. Improper
wiring could cause permanent damage to the 167 units.
Figure 10: How to Wire the Terminal Block Connectors
•
Connect the MFC cable to J1 on the 167 rear panel
•
Connect the power supply cable to J2 on the 167 rear panel
16
4
Chapter Two: Installation and Operation
How To Adjust the Gauge Factor
How To Adjust the Gauge Factor
The Gauge Factor is a multiplier which adjusts the 167 readout to display the flow rate in units
appropriate to the Full Scale of the MFC in use.
When nitrogen is used, adjustment of the Gauge Factor pot only needs to consider the
appropriate Gauge Factor (refer to Table 3 for the appropriate Gauge Factor to use).
For nitrogen, adjustment of the Gauge Factor pot = Gauge Factor (see Table 3)
When any gas other than nitrogen is used, adjustment of the Gauge Factor pot should also
incorporate a Gas Correction Factor (GCF). Chapter Three: Gas Correction Factor, beginning
on page 25, explains the GCF values, and Appendix B: Gas Correction Factors, beginning on
page 29, lists gases and their GCFs.
If the gas is not nitrogen, then adjustment of the Gauge Factor pot = (Gauge Factor) x (GCF)
Gauge Factors for a Range of MFCs
MFC F. S.
Voltage
MFC
Full Scale
Gauge
Factor
167 Display
at Full Scale
5V
10 sccm
100
10.00 sccm
5V
20 sccm
200
19.99 sccm
5V
50 sccm
50
50.0 sccm
5V
100 sccm
100
100.0 sccm
5V
200 sccm
200
199.9 sccm
5V
500 sccm
50
500 sccm
5V
1,000 sccm
100
1000 sccm
5V
2,000 sccm
200
1999 sccm
5V
5,000 sccm
50
5.0 slm
5V
10,000 sccm
100
10.00 slm
5V
20,000 sccm
200
19.99 slm
5V
50,000 sccm
50
50.0 slm
Table 3: Gauge Factors for a Range of MFCs
Note
If an MFC is calibrated with a gas other than nitrogen, then the Gas
Correction Factor is 1.00 (one) when using that gas in the process.
17
How To Adjust the Gauge Factor
Chapter Two: Installation and Operation
To determine the Gauge Factor pot adjustment value needed to correctly adjust the Gauge Factor
pot, follow these steps:
1. Look up the Gauge Factor in Table 3, page 17, for the MFC in use.
2. Multiply the Gauge Factor by the Gas Correction Factor (GCF) for the gas in use.
A. If using nitrogen (GCF = 1.00), this step is not necessary.
B. If using any gas other than nitrogen, refer to Appendix B: Gas Correction Factors,
page 29, for the GCF.
3. Hold the Gauge Factor/Flow/Set Pt. switch in the Gauge Factor position.
The 167 readout responds by displaying the current gauge factor value.
4. Using a small flat edge screwdriver to access the Gauge Factor pot on the front panel,
adjust the display until it reads the correct adjustment value.
Refer to Figure 7, page 7, for the location of the Gauge Factor pot.
5. Once the correct value is displayed, release the Gauge Factor/Flow/Set Pt. switch.
6. If appropriate, move the decimal point in the display by adjusting the rear panel Decimal
Point selector.
Refer to Figure 8, page 9, for the location of the Decimal Point selector.
Examples
A) For a 200 sccm Full Scale MFC with nitrogen: The Gauge Factor from Table 3 is 200,
and the GCF from Appendix B is 1.00, so the Gauge Factor pot adjustment is 200.
Adjustment = (Gauge Factor)(GCF for nitrogen)
= (200)(1.00) = 200
Set the display to 1999 (and adjust the rear panel Decimal Point selector so the display
reads 199.9).
B) For a 2000 sccm Full Scale MFC with methane: The Gauge Factor from Table 3 is 200,
and the GCF from Appendix B is 0.72, so the Gauge Factor pot adjustment is 144.
Adjustment = (Gauge Factor)(GCF for methane)
= (200)(0.72) = 144
Set the display to 1440 and adjust the Decimal Point selector so the display reads 144.0.
C) For a 50 sccm Full Scale MFC with nitrogen: The Gauge Factor from Table 3 is 50, and
the GCF from Appendix B is 1.00, so the Gauge Factor pot adjustment is 50.
Adjustment = (Gauge Factor)(GCF for nitrogen)
= (50)(1.00) = 50
Set the display to 500 and adjust the Decimal Point selector so the display reads 50.0.
18
Chapter Two: Installation and Operation
How To Adjust the Set Point
How To Adjust the Set Point
Set the Gauge Factor before adjusting the set point.
The Set Point pot is used to adjust the set point voltage. It is adjusted to a percent of the mass
flow controllers’ Full Scale times ten (%MFC F.S. x 10). The 167 readout controls according to
this set point when the Gauge Factor/Flow/Set Pt. switch is in the Flow position (flow mode),
and displays the flow in engineering units (sccm or slm).
The Set Point pot is adjusted by pushing the lock counterclockwise into its uppermost position,
turning the dial, then locking the dial in the desired position. The set point can be adjusted in
one of two ways: by turning the Set Point pot until the display shows the desired flow rate, or by
determining the desired Set Point pot value and setting the pot to that value. Using the 167
display is more accurate than using the Set Point pot.
To Adjust the Set Point by Adjusting the Flow Rate in the Display
1. Hold the Gauge Factor/Flow/Set Pt. switch in the set point position (labeled Set Pt. on
the front panel).
The 167 readout responds by displaying the set point flow rate in engineering units.
2. Unlock the Set Point pot by pushing the lock (black tab sticking out at the upper right
quadrant of the Set Point pot) counterclockwise into its uppermost position.
3. Turn the Set Point pot until the display shows the desired flow rate.
4. Lock the Set Point pot by pushing the lock clockwise to its lowest position.
5. Release the Gauge Factor/Flow/Set point switch.
The switch returns to its center (Flow) position, and the 167 is in flow mode.
Note
The decimal point should have been adjusted when setting the Gauge
Factor (refer to How To Adjust the Gauge Factor on page 17).
19
How To Adjust the Set Point
Chapter Two: Installation and Operation
To Adjust the Set Point by Adjusting the Set Point Pot
1. Determine what percent of the MFC Full Scale equals the desired flow.
% of MFC F.S.
=
desired flow rate
GCF of N2
x
GCFx
MFC F.S.
where GCFx = the Gas Correction Factor for gas X
Appendix B: Gas Correction Factors, beginning on page 29, lists gas correction factors.
2. Multiply the percent by 10 to arrive at the set point value.
3. Hold the Gauge Factor/Flow/Set Pt. switch in the set point position (labeled Set Pt. on
the front panel).
The 167 readout responds by displaying the set point flow rate in engineering units.
4. Unlock the Set Point pot by pushing the lock (black tab sticking out at the upper right
quadrant of the Set Point pot) counterclockwise into its uppermost position.
5. Adjust the Set Point pot to the desired value.
For example, if the desired set point value is 850 (or 85% of the MFC Full Scale), adjust
the Set Point pot as shown in Figure 11.
Window
Lock
Figure 11: The Set Point Pot
6. Lock the Set Point pot by pushing the lock clockwise to its lowest position.
7. Release the Gauge Factor/Flow/Set Pt. switch.
The switch returns to its center (Flow) position, and the 167 is in flow mode.
Note
The decimal point should have been adjusted when setting the Gauge
Factor (refer to How To Adjust the Gauge Factor on page 17).
20
Chapter Two: Installation and Operation
How To Adjust the Set Point
Examples
A). If the MFC F.S. = 100 sccm, and the desired flow rate is 100 sccm of nitrogen, then the
desired percent of F.S. is 100%.
% of F.S.
=
desired flow rate
GCF of N2
x
GCF of N2
MFC F.S.
=
1.00
100 sccm
x
1.00
100 sccm
=
100%
Multiply the desired percent by 10 (100 x 10 = 1000).
Hold the Gauge Factor/Flow/Set Pt. switch in the Set Pt. position, unlock the Set Point
pot, adjust the pot to 1000, then lock the pot.
If the Gauge Factor has been adjusted to maximize the resolution of the 167 display, then
the display will read 100.0 at full scale flow.
B). If the MFC F.S. = 100 sccm, and the desired flow rate is 50 sccm of neon (GCF = 1.46),
then the desired percent of F.S. is 34%:
% of F.S.
=
GCF of N2
desired flow rate
x
GCF of Ne
MFC F.S.
=
1.00
50 sccm
x
1.46
100 sccm
=
34%
Multiply the desired percent by 10 (34 x 10 = 340).
Hold the Gauge Factor/Flow/Set Pt. switch in the Set Pt. position, unlock the Set Point
pot, adjust the pot to 680, then lock the pot.
If the Gauge Factor has been adjusted to maximize the resolution of the 167 display, then
the display will read: 50.0 at full scale flow.
C). If the MFC F.S. = 200 sccm, and the desired flow rate is 150 sccm of neon (GCF =
1.46), then the desired percent of F.S. is 51%:
% of F.S.
=
GCF of N2
desired flow rate
x
GCF of Ne
MFC F.S.
=
1.00
150 sccm
x
1.46
200 sccm
=
51%
Multiply the desired percent by 10 (51 x 10 = 510).
Hold the Gauge Factor/Flow/Set Pt. switch in the Set Pt. position, unlock the Set Point
pot, adjust the pot to 510, then lock the pot.
If the Gauge Factor has been adjusted to maximize the resolution of the 167 display, then
the display will read: 150.0 at full scale flow.
21
How To Command the MFC Operation
Chapter Two: Installation and Operation
How To Command the MFC Operation
To command an MFC to go to full open
•
Lift the Open/Close/Flow switch and set it in the Open position
The 167 readout responds by sending a digital low to the MFC Open pin.
NOTE: Proper cabling (MKS CB147-1) is necessary to connect this low to the MFC.
To command an MFC to go to full close
•
Lift the Open/Close/Flow switch and set it in the Close position
The 167 readout responds by sending a digital low to the MFC Close pin.
Note
Proper cabling (MKS CB147-1) is necessary to connect this low to the
MFC.
To command an MFC to operate according to the set point
•
Lift the Open/Close/Flow switch and set it in the Flow position
The 167 readout responds by sending a set point voltage to the MFC.
22
Chapter Two: Installation and Operation
How To Zero the MFC
How To Zero the MFC
For mass flow controllers, any zero offset present is corrected to zero internally in the Type 167
readout and the zero-corrected signal is returned to the MFC PID (Proportional-IntegralDerivative) control circuitry. This is done to ensure that the displayed flow and actual controlled
flow do not develop offsets relative to one another.
The Zero pot on the 167 readout is for fine tuning of the MFC zero. If the MFC reading is
greater the ± 2% of the MFC Full Scale, use the Zero Control pot on the MFC to bring the
reading within 2% before using the 167 readout Zero pot.
Note
When zeroing an MFC, zero gas flow must be ensured. This can be
accomplished by turning off a valve(s) in series with the MFC.
1. With zero gas flow ensured, apply power to the 167 readout and allow it to warm up and
stabilize for at least 15 minutes.
2. Allow adequate warmup time for the MFC.
Consult the MFC operating manual for the proper warmup time interval.
3. Adjust the Zero pot on the front panel of the 167 readout until 0000 is displayed.
If unable to properly adjust the zero, use the zero pot on the MFC. After zeroing at the
MFC, use the 167 readout for a final fine tuning of the zero.
Note
If the 167 readout’s Zero pot has been adjusted to the end of its range, recenter the pot before making the above coarse adjustment at the MFC.
23
How To Adjust the Decimal Point
Chapter Two: Installation and Operation
How To Adjust the Decimal Point
Decimal point adjustment is accomplished by using the Decimal Point selector located on the
back panel of the 167 readout. This selector is used to set the appropriate decimal point in the
front panel digital display.
Note
The placement of the decimal is for your convenience - it does not affect
the signal output from the 167 readout to an MFC.
When setting the Gauge Factor, it is best to utilize all of the digits in the LED display. This
maximizes the resolution of the readout and thus the accuracy of the reading.
For example, if a Gauge Factor of 200 is desired, adjust the Gauge Factor pot so that 1999 is
shown in the display (it is not possible to display 200.0). For your convenience, the decimal may
be placed between the last two digits so that 199.9 shows in the display (199.9 is the closest to
200.0 that the LED display can show).
It is also possible to set the decimal so that 1.999 or 19.99 or 1999. is shown in the
display. Regardless of where the decimal is, the 167 readout sends out the same signal. Since a
display of 199.9 is the closest to the desired display of 200.0, it would be the best choice.
24
Chapter Three: Gas Correction Factor
General
Chapter Three: Gas Correction Factor
General
A Gas Correction Factor (GCF) is a number used to indicate the ratio of flow rates of different
gases which will produce the same output voltage from a mass flow meter (MFM) or mass flow
controller (MFC). The GCF is a function of specific heat, density, and the molecular structure of
the gases. Since flow meters and controllers are usually calibrated with nitrogen, nitrogen is used
as the baseline gas (GCF = 1). The GCF of any other gas is determined by using the following
equation:
GCFx =
(0.3106) (S)
(dx) (Cpx)
where:
GCFx = Gas Correction Factor for gas X
dx = Density of gas X, g/l (at 0° C and 760 mmHg)
Cpx = Specific heat of gas X, cal/g°C
0.3106 = (Density of nitrogen) (Specific heat of nitrogen)
S = Molecular Structure correction factor where S =
1.030
for Monatomic gases
1.000
for Diatomic gases
0.941
for Triatomic gases
0.880
for Polyatomic gases
Appendix B: Gas Correction Factors, beginning on page 29, lists the Gas Correction Factors for
commonly used gases.
Note
When using the GCF, the flow reading accuracy may vary by ± 5 %,
however, the repeatability will remain ± 0.2 % of F.S.
25
How To Determine What Range MFC to Use
Chapter Three: Gas Correction Factor
How To Determine What Range MFC to Use
Mass flow controllers are available in ranges from 10 to 50,000 sccm. To determine which range
MFC is needed, use the ratio of the GCF of nitrogen (1.00) to the GCF of the desired gas, to
determine the ratio of the flow rate of nitrogen to the flow rate of the desired gas.
Example 1
Which range MFC should be selected to flow 100 sccm of argon (Ar),?
1. Find the Gas Correction Factor of Ar (Appendix A).
1.39 is the GCF for Ar.
2. Insert the GCF of Ar in the following formula:
( GCF of N2)
(x)
=
(GCF of Ar)
(Desired flow rate of Ar)
where x is the flow rate
of nitrogen (sccm).
(1.00)
(x)
=
(1.39)
(100 sccm Ar)
x = 72 sccm N2
100 sccm of Ar will look like 72 sccm of N2 . This falls within the range of a 100 sccm MFC.
When calculating equivalent N2 flows using gas correction factors, be sure to use a flow
controller with a sufficient flow rate range. For example, if the calculated equivalent N2 flow in
the example shown above is 205 sccm, use a 500 sccm flow controller. The 500 sccm instrument
can then be calibrated such that 205 sccm N2 = full scale.
26
Appendix A: Product Specifications
Specifications
Appendix A: Product Specifications
Specifications
Cabling
To MKS MFC with a Type “D” connector: CB147-1-10
To MKS MFC with a Edge Card connector: CB147-7-10
To MKS 260PS-1 power supply: CB260-7-10
Consult MKS for cables to other MFCs or power supplies
Compatible MFCs
Any MFC employing ±15 VDC power input, and 0 to 5 VDC
set point and output signals
Dimensions
2.83” x 2.83” x 2.48” (72 mm x 72 mm x 63 mm)
Display
3½ digit LED, ½” high digits
Front Panel Controls
Flow set point
10-turn precision potentiometer
MFC zero
recessed potentiometer
Gauge Gas Correction Factor
recessed potentiometer
Open/Close/Flow switch
locking toggle switch
Gauge Factor/Set Point/Flow
switch
toggle switch (spring-loaded to flow position)
Mounting
Square panel cutout 2.7” (68 mm) per side
Operating Temperature Range
15° to 40° C (59° to 104° F)
Power Requirements
±15 VDC ±5%, 30 mA
(does not include the power required for the MFC)
Rear Panel Connectors
J1
15-pin Type “D” connector (connects to the MFC)
J2
4-pin terminal block connector (to ±15 VDC power)
Rear Panel Control
Decimal point selector switch
Due to continuing research and development activities, these product specifications are subject to change without notice.
27
Specifications
Appendix A: Product Specifications
This page intentionally left blank.
28
Appendix B: Gas Correction Factors
Appendix B: Gas Correction Factors
GAS
SYMBOL
SPECIFIC HEAT, Cp
cal/goC
DENSITY
CONVERSION
g/l @ 0oC
FACTOR
Air
---
0.240
1.293
1.00
Ammonia
NH3
0.492
0.760
0.73
Argon
Ar
0.1244
1.782
1.391
Arsine
AsH3
0.1167
3.478
0.67
Boron Trichloride
BCl3
0.1279
5.227
0.41
Bromine
Br2
0.0539
7.130
0.81
Carbon Dioxide
CO2
0.2016
1.964
0.701
Carbon Monoxide
CO
0.2488
1.250
1.00
Carbon Tetrachloride
CCl4
0.1655
6.86
0.31
Carbon Tetraflouride
(Freon - 14)
CF4
0.1654
3.926
0.42
Chlorine
Cl2
0.1144
3.163
0.86
Chlorodifluoromethane
(Freon - 22)
CHClF2
0.1544
3.858
0.46
Chloropentafluoroethane
(Freon - 115)
C2ClF5
0.164
6.892
0.24
Chlorotrifluoromethane
(Freon - 13)
CClF3
0.153
4.660
0.38
Cyanogen
C2N2
0.2613
2.322
0.61
Deuterium
D2
1.722
0.1799
1.00
Diborane
B2H6
0.508
1.235
0.44
Dibromodifluoromethane
CBr2F2
0.15
9.362
0.19
Dichlorodifluoromethane
(Freon - 12)
CCl2F2
0.1432
5.395
0.35
Dichlorofluoromethane
(Freon - 21)
CHCl2F
0.140
4.592
0.42
Dichloromethysilane
(CH3)2SiCl2
0.1882
5.758
0.25
(Table continued on next page)
29
Appendix B: Gas Correction Factors
GAS
SYMBOL
SPECIFIC HEAT, Cp
cal/goC
DENSITY
CONVERSION
g/l @ 0oC
FACTOR
Dichlorosilane
SiH2Cl2
0.150
4.506
0.40
1,2-Dichlorotetrafluoroethane
(Freon - 114)
C2Cl2F4
0.160
7.626
0.22
1,1-Difluoroethylene
(Freon - 1132A)
C2H2F2
0.224
2.857
0.43
2,2-Dimethylpropane
C5H12
0.3914
3.219
0.22
Ethane
C2H6
0.4097
1.342
0.50
Fluorine
F2
0.1873
1.695
0.98
Fluoroform
(Freon - 23)
CHF3
0.176
3.127
0.50
Freon - 11
CCl3F
0.1357
6.129
0.33
Freon - 12
CCl2F2
0.1432
5.395
0.35
Freon - 13
CClF3
0.153
4.660
0.38
Freon - 13 B1
CBrF3
0.1113
6.644
0.37
Freon - 14
CF4
0.1654
3.926
0.42
Freon - 21
CHCl2F
0.140
4.592
0.42
Freon - 22
CHClF2
0.1544
3.858
0.46
Freon - 23
CHF3
0.176
3.127
0.50
Freon - 113
C2Cl3F3
0.161
8.360
0.20
Freon - 114
C2Cl2F4
0.160
7.626
0.22
Freon - 115
C2ClF5
0.164
6.892
0.24
Freon - 116
C2F6
0.1843
6.157
0.24
Freon - C318
C4F8
0.185
8.397
0.17
Freon - 1132A
C2H2F2
0.224
2.857
0.43
Helium
He
1.241
0.1786
.- - -2
Hexafluoroethane
(Freon - 116)
C2F6
0.1843
6.157
0.24
Hydrogen
H2
3.419
0.0899
.- - -2
Hydrogen Bromide
HBr
0.0861
3.610
1.00
(Table continued on next page)
30
Appendix B: Gas Correction Factors
GAS
SYMBOL
SPECIFIC HEAT, Cp
cal/goC
DENSITY
CONVERSION
g/l @ 0oC
FACTOR
Hydrogen Chloride
HCl
0.1912
1.627
1.00
Hydrogen Fluoride
HF
0.3479
0.893
1.00
Isobutylene
C4H8
0.3701
2.503
0.29
Krypton
Kr
0.0593
3.739
1.543
Methane
CH4
0.5328
0.715
0.72
Methyl Fluoride
CH3F
0.3221
1.518
0.56
Molybdenum Hexafluoride
MoF6
0.1373
9.366
0.21
Neon
Ne
0.246
0.900
1.46
Nitric Oxide
NO
0.2328
1.339
0.99
Nitrogen
N2
0.2485
1.250
1.00
Nitrogen Dioxide
NO2
0.1933
2.052
0.74
Nitrogen Trifluoride
NF3
0.1797
3.168
0.48
Nitrous Oxide
N2 O
0.2088
1.964
0.71
Octafluorocyclobutane
(Freon - C318)
C4F8
0.185
8.937
0.17
Oxygen
O2
0.2193
1.427
1.00
Pentane
C5H12
0.398
3.219
0.21
Perfluoropropane
C3F8
0.194
8.388
0.17
Phosgene
COCl2
0.1394
4.418
0.44
Phosphine
PH3
0.2374
1.517
0.76
Propane
C3H8
0.3885
1.967
0.36
Propylene
C3H6
0.3541
1.877
0.41
Silane
SiH4
0.3189
1.433
0.60
Silicon Tetrachloride
SiCl4
0.1270
7.580
0.28
Silicon Tetrafluoride
SiF4
0.1691
4.643
0.35
Sulfur Dioxide
SO2
0.1488
2.858
0.69
(Table continued on next page)
31
Appendix B: Gas Correction Factors
GAS
SYMBOL
SPECIFIC HEAT, Cp
cal/goC
DENSITY
CONVERSION
g/l @ 0oC
FACTOR
Sulfur Hexafluoride
SF6
0.1592
6.516
0.26
Trichlorofluoromethane
(Freon - 11)
CCl3F
0.1357
6.129
0.33
Trichlorosilane
SiHCl3
0.1380
6.043
0.33
1,1,2-Trichloro - 1,2,2-Trifluoroethane
(Freon - 113)
CCl2FCClF2 or
0.161
8.360
0.20
WF6
0.0810
13.28
0.25
Xe
0.0378
5.858
1.32
Tungsten Hexafluoride
Xenon
1Empirically
NOTE:
defined
(C2Cl3F3)
2Consult
MKS Instruments, Inc. for special applications.
Standard Pressure is defined as 760 mmHg (14.7 psia). Standard Temperature is defined as 0oC.
32
Index
Index
Messages, definitions of, 1
B
MFC range, 26
Back panel, 9
O
C
Open/Close/Flow switch, 3, 8
Cabling, 27
P
Companion products, 13
Connectors, 9, 10, 11, 16, 27
Panel cutout, 6, 15
Customer support, 4
Panel mount, 13
Power requirements, 14, 27
D
Power supply, 13
Decimal point, 24
R
Decimal point selector, 9
Dimensions, 5–6, 27
Returning the product, 4, 13
E
S
Engineering units, 3
Safety procedures and precautions, 1
Environmental requirements, 14
Set point, 19
Set Point pot, 8
F
Specifications, 27
Front panel, 7
U
G
Unpacking, 13
Gas Correction Factor, 17, 25–26, 29
V
Gauge Factor, 8, 9, 17, 24
Gauge Factor pot, 3, 7
Valve commands, 10, 22
I
Z
Input power, 3, 14, 27
Zero, 23
Zero pot, 3, 7, 23
M
Manual organization, 4
33
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