Use this table to help diagnose a fault with your Series 500 handheld monitor.
If you’re unable to find the fault in the table, or the suggested fix doesn’t work, contact Technical Support.
| Fault | Possible causes | Solutions |
|---|---|---|
| No power | Lead connection broken Power supply failure Battery flat Monitor damaged Sensor head damaged | Reconnect power lead Replace 12VDC power supply Recharge battery Replace monitor Replace sensor head |
| Sensor failure when sensor new | Insufficient warm-up Air contaminated Sensor damaged | Run the sensor on full power for 24- 48 hours. If using an ozone sensor head and an ozone source is available, exposure to 100ppb for 5 minutes will speed up the decontamination process (about 30 minutes). Move the sensor to cleaner environment and check reading Replace sensor |
| Reading high under zero gas conditions | Background gas level higher than normal Interfering gas present Sensor zero drift Sensor damaged | Move sensor to clean air and check reading is zero or close to zero Move sensor to clean air and check reading is zero or close to zero ZERO CAL sensor zero grade air using the AS R42 calibration accessory Replace sensor |
| Reading higher than expected in the presence of sensor gas | Sensor correct Interfering gas present Sensor calibration lost | Check calibration of gas generator Move sensor to clean air and check reading upon exposure to known gas concentration Replace/refurbish sensor |
| Reading lower than expected reading in the presence of sensor gas | Sensor correct Sensor inlet contaminated Sensor fan failed Interfering gas present Gas reactive and decomposing before detection Local air flow too high (ozone sensors) or too low (VOC and ammonia sensors) Sensor calibration lost | Check calibration of gas generator Clean sensor inlet filter and mesh Replace sensor Move sensor to clean air and check reading upon exposure to known gas concentration Move the monitor closer to them source of the gas Modify the airflow into and around sensor head Replace/refurbish sensor |
| Reading unstable | Power supply unstable Power supply current rating incorrect Local air flow too high Environmental conditions fluctuating EMI noise picked up via USB cable and PC | Install stable power supply Install power supply with correct rating Reduce air flow Reduce fluctuations Unplug cable to determine if this reduces the instability. If this solves the problem then isolate the power on PC |
| External alarm and control doesn't work correctly | Incorrect RJ12 pins used No diode across external relay coil Diode polarity incorrect | Check pins and wire correctly Fit diode across external relay coil Fit diode correctly |
| USB communications unstable | Connections broken COM port settings incorrect Clock setting incorrect | Reconnect leads Set up COM port correctly Synchronise clock with PC. If this doesn’t work, the clock battery may be flat. Return monitor to Aeroqual for battery replacement. |
Diagnostics
Series 500 monitors have inbuilt diagnostics to detect sensor faults. If the sensor fails, it can be easily replaced by removing and installing a new sensor head. The failed sensor can be sent back to Aeroqual for replacement or disposal upon successful warranty diagnosis according to Aeroqual's Warranty Policy.
| Fault | LCD screen | 0-5V output | Control output | Low alarm output | High alarm output | Data logging |
|---|---|---|---|---|---|---|
| No fault | Valid gas reading | Reading proportional to gas reading | As set by user | As set by user | As set by user | Valid gas reading |
| Sensor failed | Sensor failure | 5V | Open | Closed | Closed | 9999 |
| Sensor aging | Valid gas reading plus sensor aging | Reading proportional to gas reading | As set by user | As set by user | As set by user | Valid gas reading |
| Communications failure | SENSOR NOT CONNECTED or N.C. or turn off when use Ni-MH battery only | 0V | Open | Open | Open | No output |
| Sensor standby | Standby symbol | 0V | Open | Open | Open | No output |