help on using a multi tester

[cptnicko]

I have just bought myself a multi tester so that I can check my wiring and that everything is working fine and earthed etc. The problem is the tester is limited as regards information on its use.

I have little knowledge about DC and AV voltage but am willing to learn before I do anything (making sure I am 100 percent knowledgeable before I begin). Can anyone help on this issue? For example, where the coloured outer coating is not visible how do I check which is earth, live and natural with the use of a tester?

Dave

 

[davelx]

What sort of "multi-tester"?

You might find this useful:

http://www.tlc-direct.co.uk/Book/8.1.1.htm

 

[cptnicko]

Just purchased it today. It is a Blackspur 3.5 digital multi tester. 5 functions, 19 rangers. Is this what you mean by what sort?

 

[cptnicko]

I have symbols on the tester such as V~ and VΩ (the symbol alongside the V may change when I post it, it looks like a Greek symbol, similar to a horse shoe) and V (hyphen with three dots underneath) and A (hyphen with three dots underneath) etc.

 

[jwilliams]

I have symbols on the tester such as V~ and VΩ (the symbol alongside the V may change when I post it, it looks like a Greek symbol, similar to a horse shoe) and V (hyphen with three dots underneath) and A (hyphen with three dots underneath) etc.

~ means AC
"hyphen with three dots underneath" means DC
"Greek symbol, similar to a horse shoe" means ohms -> resistance
V means voltage
A means amps/current

 

[davelx]

Just purchased it today. It is a Blackspur 3.5 digital multi tester. 5 functions, 19 rangers. Is this what you mean by what sort?

Yes. OK, that I call a multimeter. It's fine for some basic tests to see what is connected to what but cannot perform the full range of tests needed fto confirm the safety of an electrical installation. In particular it will not have an accurate low-ohms range, nor will it have insulation test capability.

Nevertheless, much better than nothing and useful for fault-finding, once you have learnt how to use it.

 

[sm1thson]

yep its generally called a multimeter, every DIYer should have one. the sparks have fancy ones that do proper tests for when new circuits are added etc, but you will find many uses for yours (its 1,000,000 times better than a neon screwdriver, but note when the battery symbol comes on it will give errornous results).

i googled this link for you, make sure you understand that. note that to measure amps the leads have to be in a different position and the meter basically becomes a short circuit (ie a continuous peice of wire) -you probably wont be needing that but you need to know so you dont measure volts with the lead in amps position as sparks will fly.

allways work with the circuit dead, sometimes you may need to test with it live, but try and do as many tests with the circuit dead using 'ohms'. -eg when trying to find which is the switch on a lighing circuit dont measure which have voltage, turn it off and measure the ohms to see which is the switch -much safer!

edit: ive just realised the link refers mostly to DC circuits, but the priciples of using the meter are the same. someone else can explain the difference I'm feeling lazy.

 

[cptnicko]

Many thanks all, you have been of great help