Onboard Diagnostics; Sensor Poisons - Macurco OX-12 User Instructions

Onboard Diagnostics

The OX-12 monitors all critical functions of the unit through software diagnostics that continuously test and verify unit operations. If a
problem is found, the unit will switch to a fail-safe/error mode or trouble condition. In this error mode, the Alarm relay will be activated,
the 4-20 mA current loop will go to 24 mA, the unit will display the error code, the green status indicator LED light will flash and the
buzzer will chirp intermittently. The Fan relay will also engage if the Trouble Fan Setting Option is set to "On". This is a safety
precaution. To clear this mode, simply turn off power to the unit for a few seconds, or push the ENTER/TEST switch (inside the unit).
This will cause the unit to restart the 1 minute self-test cycle.
The 4-20 mA signal can be used for troubleshooting:

0 mA is most likely a connection problem

4-20 mA is normal gas reading range (0-25% v/v)

24 mA indicates a Trouble condition
Error Codes

t01

t02

t04

t10

t20

t40

t80

t100

t200
Note: For trouble codes over 080 the display will alternate between t_1 and t00 for t100 and between t_2 and t00 for t200.
If the error mode repeats frequently, check for continuous power and proper voltage. If power is not the problem and a unit has
repeating error conditions, it may need to be returned to Macurco for service, per these User Instructions.
If the error mode indicates "Sensor warranty expired" see the Sensor Replacement section of these User Instructions.

Sensor Poisons

The gas sensor in the detector is designed with extreme sensitivity to the environment. As a result, the sensing function may be
deteriorated if it is exposed to a direct spray from aerosols such as paints, silicone vapors, etc., or to a high density of corrosive gases
(such as hydrogen sulfide, sulfur dioxide) for an extended period of time.
Sensor missing
Temperature compensation failure
EEPROM bad checksum
Bad EEPROM
Bad calibration
Factory calibration failure
Read ADC failure
Under range
Sensor warranty expired
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