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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 7th May 2018, 9:59 am   #81
mhennessy
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Default Re: Help on buying a multimeter

Quote:
Originally Posted by IanBland View Post
The most expensive came from Farnell, it's a Tenma (I think they're Uni-Ts rebadged or summat) 72-7732A. It's auto-ranging and Class IV which means you can use it standing in a puddle outdoors or whatnot.
Yes, the Tenma meters I've seen are usually UNI-Ts.

I'd hope that your expensive Tenma is better than the ones we bought. I can't remember the model number, but we only paid £30-40 for them. They lasted about 2 years of very light use before we scrapped them - meanwhile the 1980s Fluke 75s are still going strong. The faults they developed were numerous, but the "best" one would intermittently lock up, showing 0.000 in the display, irrespective of the applied voltage - obviously this is about as dangerous as it gets!

I kept the PCB from one of these, and the UNI-T model number is on the silk screen - I'll remind myself of it when I get back to work. I keep it to show people the difference between cheap junk and Fluke. The thing about UNI-T is that they do make some reasonable meters, but they also make very poor ones - so without having seen a decent review first, what you end up with really is a matter of luck.

I wouldn't place any faith in the CAT ratings either. As you'll see from my UT61E review, they are no more trustworthy than any of the super-cheap brands.
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Old 7th May 2018, 10:25 am   #82
Craig Sawyers
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Default Re: Help on buying a multimeter

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Originally Posted by IanBland View Post
My two pennorth-

I've got three. The most expensive came from Farnell, it's a Tenma (I think they're Uni-Ts rebadged or summat) 72-7732A. It's auto-ranging and Class IV which means you can use it standing in a puddle outdoors or whatnot.
I've peered in detail at the Tenma, and agree that it looks like a very nice meter. Scaling dimensions, the CE mark conforms to the style and required size of >5mm, which is refreshing. I'd be interested what fuses it uses inside.

But the manual says that it is suitable for indoor use only - so outdoors in a puddle is verboten

Ah - downloading the manual the fuses are specified as:

Fuse 1: 0.5A,1000V, fast type fuse, 10.3X38mm
Fuse 2: 10A,1000V, fast type fuse, 6.3X32mm

Which are the real deal. And a factor of four or five cheaper and more fully featured than a Fluke.

Craig
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Old 7th May 2018, 10:38 am   #83
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Default Re: Help on buying a multimeter

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Originally Posted by Oldcodger View Post
.
Fortunately, these days, most DIGITAL meters( evn the cheap ones) have an input resistance ( quoted in older analogue meters as KOHM/VOLT, with 20 KOhm/volt being a god example) in excess of 1Mohm/volt.
.
Errr..... no. DMMs have a defined input resistance, usually 10Mohm for a decent one, 1Mohm for a cheapy, not an ohms/volt (of FSD) rating.

(Actually some posh ones will have a >xxGohm input resistance selectable on low voltage dc ranges- very useful for measuring voltage across high value resistors in low voltage semiconductor circuits)

An AVO 8 on >250V range has a higher input resistance than a cheap (1Mohm) DMM.
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Old 7th May 2018, 10:42 am   #84
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Default Re: Help on buying a multimeter

As the OP has decided to leave the forums I'll close this thread.
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