Field Calibration Procedure - Macurco RD-6 User Instructions

Macurco RD-xx User Manual

7.5 Field Calibration Procedure

Note: For optimum calibration results, the unit should be in clean air, in a low ambient air flow and have uninterrupted power
for 7 days.
RD-xx has "CAL" top level menu that can be used to perform field calibration. 'tSC', 'Spn' and 'End' are sub-menu within "CAL"
menu. 'tSC' is read only menu and represents the time since last calibration. If you enter this sub-menu, it will display value in
format Y.MM. "MM" are for months and "Y" for year. E.g. if the value is 0.05 then it has been 5 months since the unit was last
calibrated. 'Spn' sub-menu is used during field calibration procedure as described in following procedure. 'End' sub-menu is
used to exit out of 'CAL' menu.
Follow the procedure below for field calibration.
1. Remove the Philips screw on the front of the RD-xx. Pull the front cover of the unit off.
2. Assemble the 1000-ppm gas cylinder, regulator together, tygon tubing and nafion tubing together.
3. Check the pressure gauge on the regulator. If you have 25-psi or less, you will need to replace the gas cylinder.
Zeroing Process:
4. Push Next 3 times to get to CAL menu and then push Enter. It will display 'tSC'. Push Next to go to '000' and push
Enter. The display flash 'Air' and current gas reading. If Zeroing process pass, it displays PAS and 0 alternatively. If
Zeroing process fails, display will flash 'Err' and '4'.
NOTE:
a. During Zeroing process make sure the sensor is not exposed to any target gas.
b. If Zeroing fails, perform Span calibration @ 1000ppm, and after approx. 30 minutes perform Zero calibration
again.
5. Place the test Hood from the regulator over the RD-xx sensor.
6. From main screen (displaying gas reading) push Next 3 times to get to the CAL menu then push Enter. It will display
"tSC". Push Next 2 times to go to "Spn" and push Enter. The display shows GAS ..
7. Turn the regulator on, opening fully to start the flow of gas to the RD-xx sensor.
8. When the sensor detects the gas, the display will flash back and forth between the gas concentration and SPn, the
calibration will progress, and the display will show the gas level for a maximum of 300 seconds.
9. When the calibration is successful, the display will flash back and forth between gas concentration and PAS, the display
will show the calibration gas level and the calibration is done.
10. If the calibration fails, the display will flash back and forth between "Err" and "2" or "Err" and "3".
a. Err2 indicates the sensor output is outside its specifications. If this occurs, check the pressure gauge on the
regulator.
i. If the pressure is less than 25 psi the flow of gas may not be adequate to properly calibrate the unit.
ii. If there is proper pressure in the cylinder repeat steps 4 through 6.
iii. If the unit fails to calibrate twice contact Technical Support: 1-844-325-3050.
b. Err3 indicates the computed response for 100ppm (calculation based on 1000ppm calibration) is higher than
response at 0ppm. If this occurs:
i. Reset and perform Zeroing and Span Calibration
ii. If the unit fails to calibrate twice contact Technical Support: 1-844-325-3050.
11. Once the calibration has passed, Turn off the regulator, remove and disassemble the cylinder and regulator.
12. Re-assemble the RD-xx (make sure the LED is aligned with the front case hole).
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