Help using a Multimeter

[I-Hate-Hulse]

Hi guys - I'm installing some Nuheat infloor electrical heating mats. To validate the warranty I need to test the Resistance and Insulation (I think they mean "Continuity") of the wires in the mat. I'll get an electrician to install the wires to the panel but I'd rather not call him in here just to use a multimeter before I thinset it down.

I think I know how to do the Resistance. Just turned it to 2000 ohm, touched the red/black leads and got a value to what it was specified on the mat. OK there.

But the insulation test has me a bit confused. Can anyone tell me:

1) What range I need to set my digital multi meter to to do this test? What do I turn the selector knob to?
2) What should appear in this display if the test is successful? Should I see OL or some sort of infinity symbol on the multimeter display?

Here are the instructions for running the Insulation Test - To ensure that the copper conductors are fully insulated:

• Acquire a digital ohm/multimeter with alligator clip attachments for easiest connection or equivalent testing device. Place one meter probe on the ground outer metallic braid
and the other probe on the conductor wire inside the white lead.
• Mat(s) should be laid out flat.
• Do not hold probes or wires in your hands.
• Confirm that the reading is OL or infinity.
• Repeat this step to check the reading between the
metallic braid and the conductor wire inside the
black lead.

Here is what my cheapo multimeter can handle:
DC V 20 V / 200V
AC V 500V
Ohm 2000 Ohm / 2000 K Ohm
Diode - Max Open Circuit Voltage 0.8Ma

Thanks in advance - I knew I should have taken electronics in high school.... (hey there were zero girls in that class!)

[Galakanokis]

Sounds like you are just checking for shorts in the circuit/wires. Set the meter to the high range of resistance and look for the OL or no value, you don't want to see numbers. You want to see that it is open (extremely large resistance). There also might be an alarm on the meter you can turn on to check for shorts.

[kermitology]

Yeah it's just a check to see if the wires are insulated. So if you have minimal resistance, then it's bad. OL or infinity, as they state, are what you're looking for.