Detcon TP-700 - Manual (Page 35)

Model TP-700
TP-700 Instruction Manual Rev. 3.5 Page 31 of 38
 Replace the plug-in H
2
S sensor.
Stability Fault
Probable Causes: Failed Sensor, empty or close to empty Cal Gas Cylinder, problems with cal gas and
delivery, or no Humidifying Tube used, failure to properly desiccant packet the sensor cell during extended
power-off periods.
 Check Heater Power Setting (should be 235 +/- 5mW at 25ºC ambient temperature).
 Verify use of span gas Humidifying Tube.
 If using Splashguard with Integral Cal Port, must use Calibration Wind Guard or air movement can
compromise span gas delivery.
 Check validity of span gas using H
2
S pull tube or other means (check MFG date on cal gas cylinder).
 Check for obstructions through stainless steel flame arrestor (including being wet, blocked, or
corroded).
 Replace the plug-in H
2
S sensor.
Clearing Fault
Probable Causes: Failed Sensor, Cal Gas not removed at appropriate time or problems with cal gas and
delivery, presence of background H
2
S, or incorrect Heater Power Setting.
 Must recover to < 5ppm in < 5 min after AutoSpan is complete
 Use bottled air (zero air) if there is a known continuous H
2
S background level.
 Verify use of span gas Humidifying Tube.
 Check validity of span gas using H
2
S pull tube or other means (check MFG date on cal cylinder).
 Check for obstructions through stainless steel flame arrestor (including being wet, blocked, or
corroded).
 Perform Heater Power Setting.
 Replace the plug-in H
2
S sensor.
Poor Calibration Repeatability
Probable Causes: Failed Sensor, use of wrong Cal Gas or problems w/ cal gas and delivery, or Interference
Gases
 Check for adequate Sensor Life.
 Check Heater Voltage Setting (should be 235±5mW at 25ºC).
 Verify use of span gas Humidifying Tube.
 Check validity of cal gas using H
2
S pull tube or other means (check MFG date on cal cylinder).
 Check for obstructions through stainless flame arrestor (including being wet, blocked, or corroded).
 Evaluate area for presence of any contaminating gases as listed in Section 2.3.
 Note the sensor’s serial # and report repetitive problems to Detcon’s Repair Department.
 Replace plug-in H
2
S sensor cell.
Unstable Output/ Sudden spiking
Possible Causes: Unstable power supply, inadequate grounding, or inadequate RFI protection
 Verify Power source is stable.
 Verify field wiring is properly shielded and grounded.
 Contact Detcon to optimize shielding and grounding.
 Add Detcon’s RFI Protection Circuit accessory if problem is proven RFI induced.