Detcon PI-700 0-500ppb - Manual (Page 13)

Model PI-700 0-500ppb
PI-700 0-500ppb Instruction Manual Rev. 0.0 Page 9 of 53
NOTE: The 4-20mA signal is held constant at 4mA for the first two minutes after power up.
Initial Operational Tests
After a warm up period of 1 hour (or when zero has stabilized), the sensor should be checked to verify
sensitivity to the specific target gas of the application (not just Isobutylene span gas).
Material Requirements
-Detcon Span Gas (See Detcon for Ordering Information). Recommended span gas is 50% of range with
Isobutylene in air or N
2
balance (250ppb Isobutylene).
-Detcon P/N 985-241100-321 In-Line Humidifying Tube 24"
a) Connect the Cal Gas to the Sample Port as shown in Figure 12. Ensure that there is a 6” Vent Tube
connected to the ‘T’ before the Humidifying Tube. Connect the humidifying Tube to the Sample Port.
b) Apply the span calibration test gas for VOC gas sensors. Adjust the Flow Regulator on the Cal Gas
Cylinder to about 1000cc/min, then adjust the Rotameter flow rate to 500cc/min. Observe that the ITM
display increases to a level near that of the applied calibration gas value.
c) Remove test gas and observe that the ITM display decreases to “0”.
Initial operational tests are complete. PI-700 VOC gas sensors are factory calibrated prior to shipment, and
should not require significant adjustment on start up. However, it is recommended that a complete calibration
test and adjustment be performed 16 to 24 hours after power-up. Refer to zero and span calibration
instructions in Section 3.4.