Datalogger to Test False Alarms on Sensor

That is correct. You don't need new wires (unless you later determine that there's a problem with the wires you already have).

It is also good advice to check the circuit with an Ohm-meter. One simple method is to disconnect the power and zone wiring at both ends. Then tie the red to black and yellow (or white) to the green at the sensor end. Now read the resistance of each pair. Each pair should be only a few Ohms and both should be about the same. If either is much higher than the other, something's afoot with your cable.

While you're at it, check the resistance between each conductor and the panel's earth ground. Some panels behave erratically if there's a low-grade short to ground on a zone loop.

Finally, hook the sensor back up to the panel, restore power (which should have been taken off before you began work, BTW) and check the voltage at the

• and - inputs to the sensor. If the cable is too long and/or too small you might have enough voltage drop to cause problems with the sensor. The sensor's instruction sheet specifies what is the acceptable DC operating voltage.

FYI, air blowing in front of (but not on) the sensor won't affect it unless the air is causing something to move about. Air blowing directly at the sensor can cause problems.

Man, great troubleshooting story... I wish I could think of one I've seen but none of mine are all that noteworthy but I hope the thread continues.