6 Troubleshooting & Maintenance
4.3.2 No alarm when a passenger carrying suspicious articles is walking through
the detector
Possible cause(s): the sensitivity may be too low; the infrared sensor might be damaged; the control unit may
not be working normally
Troubleshooting:
1
）
Check whether the connection wire between the main engine and the door plate is attached properly;
2
）
Adjust the sensitivity;
3
）
Check if the infrared sensor is fine; if there is a sensor damaged, replace it;
4
）
If everything is perfectly fine, but the problem persists, replace the control unit;
5
）
Contact the relevant technical personnel if the above doesn’t solve the problem.
4.3.3 The WTMD failed to detect the metallic items being carried
Possible cause(s): This issue may occur when the object being carried is at the threshold of the detection
sensitivity of the security checkpoint.
Troubleshooting:
1
）
Set a higher sensitivity value. Generally, if there is not strong interference, sensitivity adjustment will tackle the
problem;
2
）
If the problem persists, it is recommended to change the installation location of the WTMD or eliminate any
on-site interference (such as the electrical control box, inverter welding machine, radio frequency equipment,
and so on). The location must be changed, so that metallic objects as small as a coin could be detected.
4.3.4 False alarm occurs, and the LED failed to correctly indicate the detection zone
where the suspicious article located
Possible cause(s): the disturbance in the surrounding environment is serious; or multiple machines being
installed side-by-side are using the same frequency; or the sensitivity for metal detection in a detection zone is
lower or higher than the zones next to it.
Troubleshooting:
