Sensor errors
Aeroqual Connect and Aeroqual Cloud report two different types of error condition in the banner at the top of the screen. These are ‘sensor offline’ and ‘sensor failed’. Both error types are recorded in the monitor’s journal.
Sensor offline
A sensor offline error is usually caused by a loose power connection or a loose communications connection. Check the module connections are secure. If the power connections and the communications connections are secure, the issue may be inside the module. Contact the Aeroqual distributor in your local country for technical support.
Sensor failure
A sensor failure error can occur for different reasons. Sometimes it’s related to a sensor parameter exceeding an allowable value. If the sensor’s baseline resistance has reached the point where it’s impossible to calibrate within specifications, it should be replaced. Contact the Aeroqual distributor in your local country for technical support.
Values from incorrect time period
If you see values from an unexpected time period in Aeroqual Cloud, try these common troubleshooting checks:
- Check the time zone configuration of the monitor.
- Check the connection from the monitor to Aeroqual Cloud. Make sure the local monitor settings are compatible with your network. If using mobile, check for signal or billing issues.
- Check the monitor is powered on and is recording data in Aeroqual Connect.
Communication errors
Failure to see the WIFI network broadcast by the monitor
If you can’t see the monitor in your list of Wi-Fi networks, it’s most likely because the Wi-Fi setting is set to ‘Client Mode’ and isn’t broadcasting. To resolve this, connect to the monitor through the Wi-Fi LAN and reset the Wi-Fi mode to ‘Access Point’. Alternatively, the monitor can be reset to factory communication settings by using the USB reset procedure.
Error 500
This error is known to occur with the internal database when trying to connect to the local interface (Connect). Clear your internet browsing history and try again. Try restarting the monitor. Sometimes a component in the embedded PC needs to be replaced. Contact the Aeroqual distributor in your local country for technical support.
Internal temperature not stable
The internal temperature should remain stable at the instrument set point. See this user guide for how to check and set the internal temperature (ITemp) set point. A failure in the internal temperature is evident in the charts:
Common troubleshooting tasks
| Fault | Possible causes | Solutions |
|---|---|---|
| Gas readings | ||
| Negative readings | Insufficient warm up | Allow monitor to warm up |
| Flow leak or incorrect flow | ||
| Dirty inlet gas filter | Change filter | |
| Incorrect zero calibration | Perform zero calibration | |
| Gas readings noisy or unstable | Flow leak or incorrect flow | |
| Module is aging | Replace module | |
| Gas readings significantly different than expected | Incorrect gain or offset applied | Check the correct gain has been applied correctly |
| Incorrect calibration performed | Incorrect gas cylinder used, or gain calculated incorrectly | |
| Gas modules | ||
| NO2 or NOx values very high | Possible Ozone scrubber failure | Correct or replace scrubber |
| NO2 > NOx | Incorrect gain or offset applied | Check the correct gain has been applied correctly |
| Incorrect calibration performed | Incorrect gas cylinder used or gain calculated incorrectly | |
| Particle monitor, particle profiler & PCX | ||
| PM2.5 > PM10 | Cyclones fitted on the wrong side | Swap cyclones to correct side |
| Auto zero calibration failing on the PM10.0 | Check baseline calibration of PM10 | |
| Incorrect gain applied | Change filter | |
| Leak in flow system | Check for leaks | |
| Negative numbers | Auto zero calibration failing | Check baseline calibration of PM10 |
| Readings lower than expected | Flow rate too low | Check flow rate change pump if required |
| Dirty optics | Have optical module serviced | |
| Failed laser | Have optical module serviced | |
| Dirty sample filters | Change filter | |
PCX Error Lights
The PCX module contains two LED which can indicate module status. The main LED, which is present on all Aeroqual modules, and a secondary LED which can indicate additional states unique to the PCX module.
| LED Color | Device State | |
| Main LED | Solid Green | Normal operation |
| Slow Flashing Green | Device warming up | |
| Rapid Flashing Green | Sensor failure error | |
| Secondary LED | Solid Green | Normal operation |
| Flashing Green | Device warming up | |
| Solid Red | Sensor failure error | |
| Flashing Red | Comms error with EPC | |
| Solid Orange | Zero calibration in progress | |
| Flashing Orange | Zero check in progress |
PCX Specific Error States
The PCX module can provide more detailed error states than previous Aeroqual modules. The table below summarizes which error states the module may present, the possible cause, and the recommend action the user should take.
| Measurement Channel | Error State | Possible Cause | Recommended Action |
| Particle Mass | Aging | PM Sensor cumulative PM exceeded or zero calibration or zero check failed | · Check PM sensor connection. Return sensor to service center for PM sensor replacement. Check PM DATA5 diagnostic. |
| Failure | PM sensor comms error or PM sensor reporting an error | · Check PM sensor to see if data is present. If no data, check cable. If data present, return to service center for PM sensor replacement | |
| Particle Counts | Sensor due for replacement | Zero calibration or zero check failed | · Check PM DATA5 diagnostic |
| Failure | PM sensor comms error or PM sensor reporting an error | · Check PM sensor to see if data is present. If no data, check cable. If data present, return to service center for PM sensor replacement. | |
| Flow | Aging | Cumulative PM for flow sensor channel exceeded. | · Replace primary filter. |
| Failure | No new data from flow sensor. | · Check flow sensor connection. | |
| Pump Speed | Aging | Pump PWM outside of expected range | · Check system for leaks |
| Failure | Pump PWM is non-zero, but pump speed (tacho) reads zero | · Check pump cable connection | |
| HTEMP | Failure | No new data from inlet heater | · Check connection to heater |
| Temp/RH | Failure | No new data from T/RH sensor | · Check connection to T/RH sensor |
PCX Zero Process
The zero process in the PCX module has been improved throughout the design lifecycle. V1.2 firmware adds the concept of a ‘zero check’ vs a ‘zero calibration’.
During a zero calibration the system takes current mass at the end of the zero calibration cycle and calculates an offset based on the data reading. During a zero check the system checks to ensure the PM level drops low enough that the baseline is correct but does not apply an offset. The PCX executes an automatic zero check or calibration at start up and every subsequent 1440 minutes (24 hours), by default.
In V1.0 the firmware can only run a zero calibration. By default, this occurs at startup and at the automatic frequency as controlled in the module settings. In V1.2 firmware, the system runs a zero check at startup and daily. The zero calibration can be re-enabled as described in the module settings or executed manually via a button in Connect if required.
Depending on the version of hardware (V1.0 vs V1.2) the sample pump on/off state may also differ during a zero check or zero cycle. Due to changes in flow path to speed up the zeroing process, the sample pump will run during zero checks and zero calibrations for V1.2 hardware.
The zero calibration procedure on the PCX takes 10 minutes by default and causes the baseline to be adjusted. The zero check procedure length varies depending on the ambient levels of dust prior to the zero check, but has a minimum length of 5 minutes, and maximum length of 30 minutes. Generally, this will be around 5-10 minutes except in exceedingly dusty environments.
The module settings of the particle count channels can be used to adjust the function and the timing of zero check and calibration cycles as described below. Modules settings can be accessed via the Diagnostics and Advanced page > Module Settings tab. Modules running V1.0 or V1.1 firmware can only run zero calibrations, while modules with V1.2 firmware can run both a zero check and a zero calibration cycle. The zero check is a pass/fail of the accuracy of the zero, while the zero calibration adjusts the offset.
PCX V1.0 & V1.1 Firmware Particle Count Module Settings
In V1.0 and V1.1 firmware, the default settings will run a zero calibration 5 minutes after startup and subsequently every 24 hours.
· TIMA - Auto calibration cycle frequency (in minutes) – how often the zero calibration will run once it has started. Set this value to -1 to disable the auto zero calibration. Default: 1440.
· TIMR – Zero calibration run time (in seconds) – how long a zero calibration runs for. Default: 600.
· TEMA – Startup zero calibration delay (in minutes) – once a unit is online and running it will run a zero calibration after this many minutes. Set this value to -1 to disable the startup zero. Default: 5.0.
PCX V1.2 Firmware Particle Count Module Settings
In V1.2 firmware, the default settings will run a zero check 5 minutes after startup and subsequently every 24 hours.
· TIMA – ******Auto check cycle frequency (in minutes) – how often the zero check will run once it has started. Minimum value of 10 (or -1) required. Set this value to -1 to disable the auto zero check Default: 1440.
· TIMR – Zero calibration run time (in seconds) – how long a zero calibration runs for. Default: 600.
· TEMA – Startup zero check delay (in minutes) – once a unit is turned on and running it will run a zero check after this many minutes. Set this value to -1 to disable the startup zero check. Default: 5.0.
· PWMH – Auto calibration cycle frequency (in minutes) – how often the zero calibration will run once it has started. Minimum value of 10 (or ≤0) required. Set this value to 1440 to enable daily auto zero calibration. Default: 0.
PCX Zero Diagnostics
PCX Firmware V1.2 provides some additional diagnostic detail on the result of the most recent zero cycle (check or calibration) in the diagnostic data channels of the PM measurements. The fifth column has a diagnostic named Zero Status. This value reports the result of the most recent zero, where the values mean:
· 0 – The most recent zero cycle was a calibration that was successful.
· >0 – The most recent zero cycle was a zero check that was successful, and the value was how long for the check to complete successfully (in seconds).
· -1 – The most recent zero cycle was a zero check that failed.
· -2 – The most recent zero cycle was a zero calibration that failed.
