advertisement
Calibration
The calibration section explains how to calibrate the controller and how to zero a TSI flow station pressure transducer (optional). The Fume Hood Monitor or Controller must be calibrated, after being installed on the fume hood, to provide accurate indication of fume hood face velocity and/or exhaust flow. The FHM10
Monitor and FHC50 Controller will warn the user with a display message if it has not been calibrated.
NOTE:
This section assumes that the appropriate sensor has been correctly installed. Inaccurate readings may be detected if sensor is not installed correctly. Review the Installation Instructions and verify that the sensor is installed correctly (usually only a problem on initial set up).
The following items are needed to calibrate a Model FHM10 Fume Hood Monitor or Model FHC50 Fume
Hood Controller:
•
Masking tape
•
Tape measure
•
Portable Air Velocity Meter such as TSI V
ELOCI
C
ALC
®
Model 9545 or Model 9515.
WARNING:
The controller is disabled during calibration. Containment may not be maintained.
To begin the calibration process, enter
CALIBRATION
menu (see Software Programming if not familiar
with keystroke procedure).
Face Velocity Calibration
Face velocity can be controlled using either a sidewall sensor or sash-position sensor with a venturi valve.
Sidewall Velocity Sensor—Sensor Zero
1.
Select VEL SENSOR ZERO item.
2.
The controller will prompt to “Tape over sensor, then press
↵
.” Place a piece of tape over the velocity sensor opening to seal off air flowing past the sensor and press the
↵
soft key.
3.
The display will indicate a countdown for the automatic sensor zero procedure, which takes
120 seconds. While counting down the 120 seconds, the controller will also display the current sensor voltage.
4.
After the 120 second countdown, the controller will display “Remove tape from sensor, then press
↵
.” Remove tape from sensor and press the
↵
key to save the zero point.
Sidewall Velocity Sensor—Sensor Span
NOTE:
Always zero sensor prior to adjusting the sensor span. A comparison thermal anemometer is required to calibrate the velocity span. Confirm a good average face velocity is present in the fume face before adjusting the span.
1.
Open the fume hood sash 60% (or to working height) and let the controller reach face velocity set point.
2.
Select VEL SENSOR SPAN item (30 second countdown). After the countdown, the VEL
SENSOR SPAN submenu will be displayed.
3.
Use a thermal anemometer to traverse the open sash area and obtain the average face velocity of the air passing into the hood.
49
4.
Compare the thermal anemometer reading to the
SPANNED VEL
reading on the controller.
5.
At the ENTER SPAN FACT menu item, press the quick keys to adjust the factor until the
SPANNED VEL
reading on the controller display matches the thermal anemometer velocity.
6.
Press the
ENTER (
↵
)
soft key to save the sensor span calibration.
NOTE
: To verify proper calibration, re-enter
VEL SENSOR SPAN
item and compare
SPANNED VEL reading to a new thermal anemometer traverse.
7.
Exit menu, sidewall sensor calibration is complete.
WARNING:
Calibrating the sidewall velocity span on the controller may be an iterative process that takes 1 to 3 trials to get an accurate calibration. After adjusting the span factor, check the calibration to verify an accurate calibration.
Sash Position Calibration
1.
Calibrate flow using LOM VENTURI Calibration section.
2.
Calibrate vertical sash sensor using CALIBRATE SASH POT section.
3.
Enter
SASH FLOW CONTROL
item.
4.
Controller will prompt “Raise sash to 24 inches height then press
↵
.” Open the sash(es) to the 24-inch height and press the
↵
key. a.
The FHC50 controller will display following items:
Desired Flow
Show Sash % Open
Actual Flow
Save & Continue
Set flow for
Flow set point to achieve desired face velocity
Readout of current sash % open
Readout of current measured flow
Use to save data point
Desired face velocity b.
Perform a face velocity traverse using a thermal anemometer. Compare the face velocity traverse reading to the face velocity set point. c.
Adjust the Desired Flow to change the flow control set point for the 24-inch sash position until actual face velocity matches the Set flow for set point. d.
Repeat steps b. and c. as needed before selecting Save & Continue to save the high sash position calibration.
5.
Controller will prompt “Lower sash to 12 inches height then press
↵
.” Lower the sash(es) to the
12-inch height, so the fume hood bypass (if present) is just covered, and press the
↵
key. a.
The FHC50 controller will display following items:
Desired Flow
Show Sash % Open
Actual Flow
Save & Continue
Set flow for
Flow set point to achieve desired face velocity
Readout of current sash % open
Readout of current measured flow
Use to save data point
Desired face velocity b.
Perform a face velocity traverse using a thermal anemometer. Compare the face velocity traverse reading to the face velocity set point.
50 Part Two
c.
Adjust the Desired Flow to change the flow control set point for the 24-inch sash position until actual face velocity matches the Set flow for set point. d.
Repeat steps b. and c. as needed before selecting Save & Continue to save the sash mid-point calibration.
6.
Controller will prompt “Lower sash to 2 inches height then press
↵
.” Lower the sash(es) to the 2-inch height, so the sash(es) are nearly closed, and press the
↵
key. a.
The FHC50 controller will display following items: b.
Perform a face velocity traverse using a thermal anemometer. Compare the face velocity traverse reading to the face velocity set point.
Desired Flow
Show Sash % Open
Actual Flow
Save & Continue
Set flow for
Flow set point to achieve desired face velocity
Readout of current sash % open
Readout of current measured flow
Use to save data point
Desired face velocity c.
Adjust the Desired Flow to change the flow control set point for the 24-inch sash position until actual face velocity matches the Set flow for set point. d.
Repeat steps b. and c. as needed before selecting Save & Continue to save the sash closed calibration.
7.
Controller will display “Sash position vs. flow is done calibrating. Press
↵
.” Press the
↵
key to save calibration and continue.
Flow Calibration
Flow can be measured using a Pressure Flow Station, Linear Flow Station, LOM Venturi, 6-Pt Venturi, or
Calculated from face velocity and open sash area.
Pressure Flow Station Calibration
NOTE:
Flow stations are optional and may not be installed in your system.
1.
Enter CALIBRATE FLOW item.
2.
Set
FLO STA AREA
to the duct area at the flow station location.
3.
Set
FLO STA PRESS FS
to match the range of the pressure transducer used.
Flow Station Pressure Transducer Zero
1.
Disconnect tubing between pressure transducer and flow station.
2.
Select FLO STA PRESS ZERO menu item.
3.
Press the
ENTER
(
↵
)
soft key. Flow zero procedure, which takes 10 seconds, is automatic.
During the 10 second flow zero procedure, the display will indicate the current flow station pressure transducer voltage.
4.
Connect tubing between pressure transducer and flow station.
Technical Section
51
Low Flow Calibration
1.
Set FLO STA FS V to match the voltage output (0 to 10V or 0 to 5V) of the pressure transducer used.
2.
Close the sash.
3.
Select
FLO STA LO CAL
to enter a submenu with the following items:
FLO STA LO SETPT
PRESS ZERO VOLTAGE
PRESSURE VOLTAGE
MEASURED FLOW
ENTER ACTUAL FLOW
Damper position for low flow calibration
Voltage from pressure transducer during Flow Station Pressure
Transducer Zero
Current voltage from pressure transducer
Current flow rate
Input actual flow as measured with reference instrument here
5.
With the
FLO STA LO SETPT
at 0% (default), observe the
PRESSURE VOLTAGE
displayed on the screen, or use a voltmeter to read the voltage at the pressure input terminals 7-8 on the back of the controller.
6.
Slowly
increase
the
FLO STA LO SETPT
percentage value to adjust the damper position until the PRESSURE VOLTAGE (pressure transducer output) shows the first noticeable increase in voltage from the 0% position. A general rule of thumb is that the voltage change should occur with the damper between approximately 10 to 30% open.
NOTE:
Adjusting the FLO STA LO SETPT with the quick keys allows the
PRESSURE VOLTAGE to be displayed in real time.
7.
For reference only, the MEASURED FLOW item will display the default measured flow based on the current settings of the flow station (duct area, etc.).
8.
Determine the actual flow with a duct traverse.
9.
Enter the actual flow measurement under the
ENTER ACTUAL FLOW
menu item.
10.
Press the
ENTER
(
↵
) soft key to save the flow data.
11.
The low flow calibration is complete. Exit the menu with the
ESC
key.
High Flow Calibration
1.
Enter CALIBRATION FLOW menu and raise the sash height to approximately 18 inches
(sash stop).
2.
Select
FLO STA HI CAL
to enter a submenu with the following items:
FLO STA LO SETPT
PRESS ZERO VOLTAGE
PRESSURE VOLTAGE
MEASURED FLOW
ENTER ACTUAL FLOW
Damper position for low flow calibration
Voltage from pressure transducer during Flow Station Pressure
Transducer Zero
Current voltage from pressure transducer
Current flow rate
Input actual flow as measured with reference instrument here
3.
With the FLO STA HI SETPT at 100% (default), observe the PRESSURE VOLTAGE displayed on the screen, or use a voltmeter to read the voltage at the pressure signal transducer input terminals 7-8 on the back of the controller.
4.
Slowly
decrease
the FLO STA HI SETPT percentage value to adjust the damper position until the
PRESSURE VOLTAGE
(pressure transducer output) shows the first noticeable
decrease
in
52 Part Two
voltage from the 100% position. A general rule of thumb is that the voltage change should occur with the damper between approximately 70 to 90% open.
NOTE:
Adjusting the FLO STA HI SETPT with the quick keys allows the
PRESSURE VOLTAGE to be displayed in real time.
5.
For reference only, the MEASURED FLOW item will display the default measured flow based on the current settings of the flow station (duct area, etc.).
6.
Determine the actual flow with a duct traverse.
7.
Enter the actual flow measurement under the
ENTER ACTUAL FLOW
menu item
8.
Press the
ENTER
(
↵
)
soft key to save the flow data.
9.
The high flow calibration is complete. Exit the menu with the
ESC
key.
NOTE
to verify flow station calibration.
Linear Flow Station Calibration
NOTE:
Flow stations are optional and may not be installed in your system.
1.
Enter
CALIBRATE FLOW
item.
2.
Set FLO STA AREA to the duct area at the linear flow station location.
3.
Set
FLO STA TOP VEL
to match the range of the linear flow station used.
4.
Set FLO STA FS V to match the voltage output (0 to 10V or 0 to 5V) of the linear flow station used.
5.
Linear flow station calibration should be complete. Exit the menu.
NOTE
: Use BALANCE MODE to verify flow station calibration.
LOM Venturi Calibration
NOTE:
LOM Venturi Valves are optional and may not be installed in your system.
1.
Obtain the venturi valve minimum and maximum flow, either by reading the label on the venturi valve or by performing duct traverses when the venturi valve is fully closed and fully opened.
2.
Enter CALIBRATE FLOW item.
3.
Set
VENTURILOM MIN
to the minimum venturi valve flow.
4.
Set VENTURILOM MAX to the maximum venturi valve flow.
5.
LOM Venturi Calibration can be adjusted using the
Flow KFactor
item.
6.
LOM venturi valve calibration is now complete. Exit the menu.
NOTE
: Use BALANCE MODE to verify LOM Venturi calibration.
6Pt Venturi Calibration
NOTE:
6Pt Venturi Valves are optional and may not be installed in your system.
If venturi valve flow data cannot be obtained from venturi valve label, perform duct traverse with venturi valve at 0%, 20%, 40%, 60%, 80% and
DIAGNOSTICS
menu).
1.
Obtain the venturi valve calibration data by reading the label on the venturi valve.
2.
Enter
CALIBRATE FLOW
item.
Technical Section
53
3.
Enter venturi valve minimum flow in item
VENTURI PT1
.
4.
Enter 2nd point flow in item VENTURI PT2 .
5.
Enter 3rd point flow in item
VENTURI PT3
.
6.
Enter 4th point flow in item VENTURI PT4 .
7.
Enter 5th point flow in item VENTURI PT5 .
8.
Enter 6th point flow in item
VENTURI PT6
.
9.
6pt venturi valve calibration is now complete. Exit the menu.
NOTE
to verify 6Pt Venturi calibration.
Calculated Flow Calibration
NOTE:
Calibrating Calculated Flow requires first calibrating the Face Velocity using the Sidewall Sensor and calibrating the Sash Pot.
1.
Enter
CAL SASH AREA
menu item.
2.
Controller will display current sash position and prompt “Fully close sash then press
↵
.” Close the sash and press the
↵
key.” After closing the sash(es) and pressing the
↵
, controller will count down for 5 seconds while it allows control to stabilize.
3.
Controller will prompt to “Enter Actual Flow”. Perform a duct traverse or otherwise measure fume hood exhaust volume and enter it into the controller.
4.
Press the
ESC
key to continue.
5.
Controller will display current sash pot position and prompt “Fully open sash then press
↵
.” Open the sash and press the
↵
key.” After opening the sash and pressing the
↵
, controller will count down for 5 seconds while it allows control to stabilize.
6.
Controller will prompt to “Enter Actual Flow”. Perform a duct traverse or otherwise measure fume hood exhaust volume and enter it into the controller.
7.
Press the
ESC
key to continue.
8.
Controller will display “Sash area vs position is calibrated. Press
↵
.” Press the
↵
key to save calibration.
NOTE:
Use BALANCE MODE to verify Calculated Flow calibration or use
CALIBRATE FLOW item to adjust the
FLOW K-FACTOR
.
Sash Opening Calibration
The Sash Opening may be calibrated using a Sash Pot (Vertical Sash Sensor).
Calibrate Sash Pot
1.
Enter CAL SASH POT item.
2.
Controller will display current sash pot voltage and prompt “Fully close sash then press
↵
.” Close the sash(es) and press the
↵
key.
3.
Controller will display current sash pot voltage and prompt “Fully open sash then press
↵
.” Open the sash(es) and press the
↵
key.
4.
Controller prompts “Sash position sensor is calibrated. Press
↵
.” Press the
↵
key to save calibration and exit the menu.
54 Part Two
advertisement
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Related manuals
advertisement