Regular inspections (monthly) are recommended and consist of:
- visual inspection of the road condition around the sensors
- measurement of the capacitance and resistance of the piezoelectric sensors
- measurement of the resistance (and inductance if possible) of the inductive loop sensor
- check of battery condition and state of charge
- check of system functionality via the front panel keypad and display
- check of vehicle record via the front panel display and visible passing traffic.
If the road conditions around the sensors show signs of cracking and break-up immediate repairs utilising epoxy or bituminous repair material are recommended. A low viscosity loop sealant such as Bondo 606 or a low viscosity epoxy such as Global PX768 should be poured into any cracks and then squeegeed smooth.
Any loose asphaltic material should be wire brushed away prior to pouring the sealant material in the cracks.
Be careful not to raise the profile of the sensor.
The sensor should be tested for capacitance and resistance and the results logged on the data sheet for the sensors.
TDC Systems 2005, ‘BL piezo electric sensor installation’, TDC Systems, North Somerset, United Kingdom