How do I install a Free Exit Probe?

Step 1

Locate the center of the driving surface and the desired distance away from the gate. A typical distance is 50’ to 100’. The amount of lead-in cable ordered on the Diablo Free Exit Probe will typically determine your maximum distance from the gate. Care should be taken to ensure that the sensor is not within 15 feet of a manhole lid (or other metallic lid) in the driving surface.

Step 2

Core drill a 1½” to 2” hole at least 6” deep at the location identified in Step 1. Saw-cut a slot at least ¼” wide and 1” deep from the drilled hole to the edge of the roadway. If installing at the side of the roadway, this step is skipped and a 3” trench is dug to where the Diablo Free Exit Probe will be installed at the side of the roadway.

Step 3

Install the Diablo Free Exit Probe sensor and route the lead-in cable back to the control box where the detector is installed. If performing the normal installation, the sensor should be placed in the drilled hole and then filled with sand to within 1” of the roadway surface. The remaining portion of the drilled hole and the saw slot should then be filled with loop sealant or another appropriate medium.

Step 4

Using an ohmmeter, measure the resistance between the two wires of the sensor. For a good sensor, the resistance should be between 1.5 and 7 ohms. If the reading is not between these values, the sensor is defective or the lead-in cable has been damaged. In either case, the sensor will need to be replaced with a functional sensor.

Step 5

If performing the normal installation, the remaining portion of the drilled hole and the saw slot should then be filled with loop sealant or another appropriate medium. Run the lead-in cable from the exit point in the driving surface to the operator. Installing a conduit will provide an additional layer of protection.

Step 6

Connect the sensor to the loop terminals of a correctly wired Diablo Controls detector.

Step 7

Use a vehicle to confirm that a vehicle is detected at the desired locations. Be sure to test as far to both sides of the driving surface as possible with the smallest expected vehicle. This is especially important if you used the side-of-roadway installation method. If you used the side-of-roadway installation method and cannot detect vehicles at all desired locations, a second sensor on the other side of the roadway may be required for reliable operation. This second sensor should be connected to its own detector. Connecting it to the same detector as the first sensor will cut the sensitivity for both sensors in half.