Just lucked into a used fluke dmm for what I think is a good price. However, one of the leads it came with is bent and beat up. Best to order a new set of fluke brand or radio shack types are fine? Or are there better options?
DMM Leads-do they matter
- Thread starter Vortus
- Start date
HKJ
Flashaholic
DMM leads do matter, especially if you are using them for dangerous voltages.
There are many difference between test leads and not all of them depends on price:
The tip of the probe, better probes do usual make better/easier contact (This depends on the surface of the tip).
The tip, some probes has a very sharp point, making it easier to get good contact, other is more rounded in the tip.
The cable, better probes uses soft silicon wires.
The resistance, some probes has high resistance other low, for current you want a very low resistance, for voltage it does not matter.
Safety, brand names probes follows the marked safety CAT, cheap probes does not always do it. This is only relevant measuring on mains or higher voltages.
General construction quality, a good test lead will last longer.
Fluke does make good test leads, but there is also other brands, but they are just as expensive.
There are many difference between test leads and not all of them depends on price:
The tip of the probe, better probes do usual make better/easier contact (This depends on the surface of the tip).
The tip, some probes has a very sharp point, making it easier to get good contact, other is more rounded in the tip.
The cable, better probes uses soft silicon wires.
The resistance, some probes has high resistance other low, for current you want a very low resistance, for voltage it does not matter.
Safety, brand names probes follows the marked safety CAT, cheap probes does not always do it. This is only relevant measuring on mains or higher voltages.
General construction quality, a good test lead will last longer.
Fluke does make good test leads, but there is also other brands, but they are just as expensive.
I do have the occasional car tinkering or some other job for it. But its primary duty will be for me or the wife to check our light batteries. For current, it came with a fluke 80i-410 AC DC Clamp, which is for measuring current from what I read on the guide you posted so that's covered. Not sure why this last part went italic, guess I clicked something while typing. The dmm is an older 23 series II. But ill look around at our local shops today before ordering online, hopefully something will be around.
When checking specs, that ones I have found are rated for 10A. I know at least one light of mine is pushing over 10A, some future will be more than that. Will that fry the leads, or the dmm? Are there brands for higher?
HKJ
Flashaholic
The current clamp looks like it only has a 400A range, it must be some very large lights you want to measure current on :)
That a test lead is rated for 10A, does not make it good for 10A, you have to know what size wire is used inside them. (The best test leads for currents is home made).
Generally you do not want to overload the DMM, the fuses in a Fluke is rather expensive.
Home made current cable:
2 banana plugs and 2x20cm thick wire (As thick as can be mounted in the banana plugs). A shop with high end car audio probably has the parts.
You do only use plugs on one end of the wire.
That a test lead is rated for 10A, does not make it good for 10A, you have to know what size wire is used inside them. (The best test leads for currents is home made).
Generally you do not want to overload the DMM, the fuses in a Fluke is rather expensive.
Home made current cable:
2 banana plugs and 2x20cm thick wire (As thick as can be mounted in the banana plugs). A shop with high end car audio probably has the parts.
You do only use plugs on one end of the wire.
Heh, well, I was thinking more when testing other things on the light, if it has 15 or so amps running through it, would it fry the leads if checking voltage. Never used a clamp before, so that will be a learning exp into itself. A 400 amp light....... I don't think I would want to mess with the innards of something that would turn me to ash if I messed up.
HKJ
Flashaholic
Voltage measurement is nearly always uA current or even less, that will not fry any probes or DMM's. It does not matter how much current is running outside the DMM.
Most clamps only works with high current. You can some some regular clamps that can be use down to 1A and still maintain some resolution (It is also possible to get specialty clamps for lower currents, but they are usual expensive).
The clamp you have looks like it works best at 50A and upwards, when you need some resolution.
I would also have some problems supplying it, my largest power supply is only 50A.
One place where you can use a 400A clamp is the measure the current your car draws when starting.
aus_sparky
Newly Enlightened
10A is standard for most quality DMM's. As HJK stated, you won't fry the leads or meter as normally they have a built-in fuse for protection (the Flukes definitely do). For higher currents, that is why you have clamp meters, but you would have to rig something up in order to record the current drawn.
In regards to test leads, I can definitely recommend Fluke leads. I use meters nearly everyday in my profession and in the last 20 odd years, the number of times I have replaced my fluke meter leads can probably be counted on one hand (wouldn't be any more than 10 times). The internal resistance of any set have never been more than 0.1 ohms. I've always been a fan of the Fluke meters.
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Well, got a set of TL71 leads from fluke, not as pricey as thought, or as cheap as I hoped from our local graybar. I have a super cheap auto parts store meter, another that's better than that but still not as good, a .02 difference with the both of them on battery voltage. Bit surprised tbh. As it means my readings have been low for quite a while, and the new charger I'd planned on returning for being to high may be within spec. Thanks for the help, this thing is huge compared to my others, esp with the rubber cover on it, but its 100% better.
Illum
Flashaholic
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