It is recommended that each installation is checked at least once every six months.
This should include:
- pavement integrity (depressions, potholes, cracks)
- piezoelectric sensor and strain gauge installation (e.g. exposed or broken sensors and/or cables)
- sensitivity and quality of signal from piezoelectric sensors and strain gauges (e.g. insulation resistance, inductance)
- cabinet and/or enclosure condition and security (clean if necessary)
- if necessary the lane needs to be closed for closer inspection and repairs (e.g. filling of cracks, fixing or replacing sensors and cables)
- inspection of loggers, solar power system (if fitted), power supplies, batteries, surge protectors and modems (clean if necessary)
- observing traffic for about one hour for comparison of actual traffic with logged data
- documentation on relevant forms (WIM maintenance visits, volume and classification record comparison, adjustments made to sensor gains and thresholds).