GDS GASMAX CX, Руководство по эксплуатации и обслуживанию, Страница: 32 / 54

GASMAX CX Operation & Maintenance Manual, Revision 1.0
Page 32
8 TROUBLESHOOTING
TOXIC SENSOR INDICATES FAULT OR OVERRANGE

Certain toxic sensors indicate off ‐ scale low or high at power up and quickly drift towards zero.
This is normal behavior.

Toxic sensors showing constant FAULT: If local, remove sensor and examine for moisture or
discoloration. Replace sensor if wet or discolored. If remote, check sensor cable and junction box
for moisture or standing water. Remove sensor and examine for moisture or discoloration.
FAULT indication generally indicates sensor useful life is exhausted.

Toxic sensors left unpowered for more than 3 months are subject to accelerated degradation and
may demonstrate a permanent loss of sensitivity.
TOXIC SENSOR WILL NOT CALIBRATE

Sensor reading during zero calibration exceeds upper limit of zero – sensor is defective and
should be replaced.

Sensor reading during span calibration too low – sensor may be defective. However, it may be
possible to temporarily continue operation by increasing PREAMP GAIN.
BRIDGE SENSOR INDICATES FAULT OR OVERRANGE

Catalytic bead combustible sensors generally indicate off ‐ scale high at power up and quickly drift
towards zero as they reach operating temperature. This is normal behavior.

Combustibles sensors showing constant OVERRANGE may have defective bead. If remote, check
wiring for correct excitation voltage at sensor. Replace sensor.
BRIDGE SENSOR WILL NOT CALIBRATE

Sensor reading during zero calibration exceeds limits – readjust SENSOR BALANCE to reset zero if
possible. If not, sensor is defective and should be replaced.

Sensor reading during span calibration too low – sensor may be defective. However, it may be
possible to temporarily continue operation by increasing PREAMP GAIN. See Section 8.2 for
more details.