YOKOGAWA ZR22G, ZR402G split zirconia oxygen/humidity analyzer

Detector connection: including sensor signal (CELL ±), thermocouple (TC ±), cold junction compensation (CJ ±), heater power supply (HTR) wiring.

External interfaces: analog output (4-20mA), contact input/output (control calibration, alarm, etc.), HART communication (refer to dedicated documentation).

Operation and Calibration Process

（1） Startup process

Pre inspection: Confirm that there is no leakage in the pipeline, the wiring is correct, and the valve status is normal.

Power supply startup: Connect the converter power supply, and the sensor begins to preheat (about 20 minutes, target temperature 750 ℃).

Parameter confirmation: Check the initial parameters such as converter type (oxygen/humidity), detector type, sample gas type (wet/dry gas), output range, etc.

Output inspection: Confirm that the current circuit (4-20mA) and contact I/O function are normal.

（2） Calibration operation (core process)

1. Calibration preparation

Gas requirements: Zero gas (0.95-1.0 vol% O ₂+N ₂), span gas (clean and dry air, dew point ≤ -20 ℃).

Flow setting: Calibrate air flow rate of 600 ± 60 ml/min, reference air flow rate of 800-1000 ml/min.

2. Calibration mode

Applicable scenarios for mode operation mode

Manual calibration is performed by manually controlling the gas valve through the ZO21S/ZA8F unit, and completing the calibration system 1/2 according to the touch screen prompts. Manual intervention is required

Semi automatic calibration of touch panel or touch input startup, completing calibration system 3 according to preset time, reducing manual operation

Automatic calibration is automatically executed at set intervals without the need for manual intervention. System 3 operates continuously for a long time

3. Core calibration steps

Span calibration: Introduce span gas and confirm calibration after the value stabilizes.

Zero calibration: Introduce zero gas and complete the calibration in the same way.

After calibration: Close the calibration gas valve and wait for the output to stabilize (default 10 minutes).

（3） Key parameter settings

1. Output settings

Oxygen analyzer: Set oxygen concentration values corresponding to 4mA (minimum range) and 20mA (maximum range), supporting linear or logarithmic output modes.

Humidity analyzer: Set the humidity (volume fraction or mixing ratio) corresponding to 4mA/20mA, and input the measured gas temperature and pressure to calculate the relative humidity and dew point.

2. Alarm setting

Supports four levels of alarms: high high, high, low, and low low. Alarm thresholds, hysteresis values (0-9.9 vol% O ₂, etc.), and delay times (0-255 seconds) can be set.

Alarm output: 4 contact outputs that can be assigned to alarm, fault, calibration, and other states.

Maintenance and troubleshooting

（1） Regular maintenance

1. Daily maintenance (recommended cycle)

Cleaning: Calibration gas pipeline (anti clogging), detector dust filter (K9471UA).

Inspection: Pipeline leakage, valve status, and cable connection tightness.

2. Regularly replace components

Precautions for component replacement

The zero gas calibration ratio of the sensor component exceeds 100 ± 30%, and the span gas calibration ratio exceeds 0 ± 18%; When the internal resistance of cells significantly increases, the metal O-ring (K9470BJ) and contact (E7042BS) must be replaced simultaneously

Abnormal resistance of heater unit (≤ 90 Ω is normal), unstable heating temperature at 750 ℃, please refer to the dedicated heater manual (IM 11M12A01-21E)

Before replacing the fuse converter with a blown fuse (specification 3.15A, Part No.A1113EF), it is necessary to investigate the short circuit fault

（2） Common faults and solutions

1. Error fault (Error code)

Key points for troubleshooting the causes of error codes and malfunctions

Error 1 Cell voltage fault (<-50mV) Check CELL ± wiring, sensor damage, internal wiring of detector

Error 2: Heater temperature fault (below 730 ℃ or above 780 ℃). Check the heater resistance, thermocouple wiring polarity, and cold end temperature (-25-155 ℃)

Error 3: The A/D converter has malfunctioned and restarted the device. If the error persists, please contact after-sales service

Error 4: Memory failure. Restart the device, but the error still persists. Contact after-sales service for assistance

2. Alarm fault (Alarm code)

Key points for troubleshooting the causes of alarm code faults

Alarm 6 zero calibration coefficient abnormality (exceeding 100 ± 30%) confirms zero gas concentration, calibration gas flow rate, and sensor contamination situation

Abnormal calibration coefficient of Alarm 7 span (exceeding 0 ± 18%) confirms span gas concentration, pipeline leakage, and sensor aging

Alarm 8 calibration stability timeout check calibration air flow rate, pipeline length/diameter, sensor response speed

Alarm 10 Cold End Temperature Abnormal (＜ -25 ℃ or ＞ 155 ℃) Check the wiring of the cold end sensor and the ambient temperature of the detector

3. Abnormal measurement values

High measurement value (oxygen analyzer): reference gas humidity changes, calibration gas leakage, abnormal increase in sample pressure.

Low measurement value (oxygen analyzer): zero gas leakage, combustible components in sample gas, sensor damage.