Installation
Verify that all detection zones have been installed. |
Verify that loop sawcuts are finished and level with roadway without excess epoxy. |
Verify all equipment is properly grounded. |
Lanes
Verify that the detection works properly for each lane that loops are installed.
Piezo Loops
Using a LCR meter, verify that the capacitance is within the tolerances specified by the manufacturer. |
Using a LCR meter, verify that the dissipation factor is within the tolerances specified by the manufacturer. |
Verify that installed piezo sensors are class II (used to collect axle classification data). |
Verify that sensor misses per lane shall not exceed the requirements of DTD during the test period. |
Verify that loop continuity must not exceed 1 ohm. |
Verify that voltage for a front axle of a car is not less than 80 mV. |
Data Retrieval
Verify that real-time vehicle viewing per selected lane can be performed. |
Verify that system data retrieval does not impact data collection operation. |
Verify that device supports collection of data for opposing lanes of traffic. |
Accuracy
Verify that piezos and loops were tested under actual traffic conditions. |
Verify that one week of data was collected. |
Verify that the volume count is within +/- 10 percent accuracy for the site compared to historical data. |
Verify that the vehicle classification type is within +/- 10 percent accuracy for the site compared to historical data. |
Verify that sensor misses do not exceed 1 percent in each lane during the test period. |