Macurco TX-6-AM User Instructions page 22

FIELD CALIBRATION PROCEDURE
Note: For optimum calibration results the unit should be in clean air and be in a low ambient air flow.
Zero the Sensor
1. Ensure that the ambient air has less than 0.1 ppm NH3 before proceeding with Zeroing the sensor. Remove the Philips screw on
the front of the TX-6-AM. Pull the front cover of the unit off.
2. To select Calibration Zero Mode (000), from normal mode, press the Next button three times to get to CAL or Calibration Mode.
3. Then press the Enter button to get to "000" - Calibration Zero Mode.
4. Press the Enter button and the display will read the current gas level alternating with 000 (blinking) indicating zero calibration in
progress (max 165 sec).
5. If the process is successful, the display will read 0 alternating with PAS (blinking) Zero Calibration complete.
6. If the process was not successful the display will read the current gas level alternating with FAil (fail) (blinking). If this occurs,
repeat steps 2 through 4. If the sensor fails to zero twice contact Technical Assistance: 1-877-367-7891.
Note: The display may just go back to 000 if the process is unsuccessful because the sensor response is too negative or if gas is
present.
7. To return to Normal Mode press Enter and then press Next until "End" is displayed. Press Enter to return to Normal Mode.
Calibration
1. Remove the Philips screw on the front of the TX-6-AM. Pull the front cover of the unit off.
2. Assemble the 25 ppm gas cylinder and regulator together.
3. Check the pressure gauge on the regulator. If you have 25-psi or less you will need to replace the gas canister.
4. Place the test Hood from the regulator over the gas sensor.
5. Push Next 3 times to get to the CAL menu then push Enter. Press Next once to get to Span mode then press Enter, the display will
flash back and forth between gAS and the current gas level.
6. Start applying 25 ppm gas to the gas sensor by turning on the valve on the regulator.
Note: The sensor will look for the gas for 90 seconds. If no gas is applied or detected in that time, the display will return to CAL.
7. When the sensor detects the gas, the display will flash back and forth between the gas concentration and SPn, then the calibration
will progress and the display will show the gas level for a maximum of 165 seconds.
8. When the calibration is successful, the display will flash back and forth between the gas concentration and PAS, then the display
will show the calibration gas level and the calibration is done.
9. If the calibration fails, the display will flash back and forth between the gas concentration and FAil (fail). If this occurs, check the
pressure gauge on the regulator. If the pressure is less than 25 psi the flow of gas may not be adequate to properly calibrate the
unit. If there is proper pressure in the cylinder repeat steps 4 through 6. If the unit fails to calibrate twice contact Technical
Assistance: 1-877-367-7891
10. Once the calibration has passed, remove gas and disassemble the cylinder and regulator.
11. Re-assemble the TX-6-AM (make sure the LED is aligned with the front case hole). Calibration is complete
12. See Calibration Flowchart on the inside of the housing.
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