# Current Measurement Rating

Discussion in 'General Electronics Discussion' started by Navivanuva, Jul 9, 2015.

1. ### Navivanuva

20
0
Mar 3, 2013
Hi, newbie here.

I have a multimeter (Sanwa CD771). It has max current measurement of 10A at 1000V. In my understanding, it means that i can measure up to 10000 watt. If thats true, does it mean that I can measure current higher than 10A at lower voltage? Lets say, 12v at 20A. Please enlight me masters . Thanks

2. ### davennModerator

13,654
1,888
Sep 5, 2009
no .... 10A is the max ( well it is for most general multimeters)

3. ### Navivanuva

20
0
Mar 3, 2013
Thanks for the quick reply. Would u mind explaining why?

4. ### Colin Mitchell

1,417
312
Aug 31, 2014
1. Because the wire inside the meter will get too hot if more than 10 amps flows.
2. Because the program inside the meter may only be designed to read up to 10 amp.
But you can try 12 amps and see if the reading is 12

5. ### Harald KappModeratorModerator

10,383
2,267
Nov 17, 2011
Plus there is probably a fuse that will blow at currents >10A.

The misunderstanding comes from a wrong interpretation of the meter's ratings. If can measure either up to 10A or up to 1000V. But not both simultaneously.
At 10A, there will be a very small voltage drop (a few hundred millivolt) to avoid overloading the meter and to minimize the influence of the meter's voltage drop on the circuit being measured.
At 1000V there will be a very small current (a few µA), again to avoid overloading the meter and to minimize the influence of the meter's current consumprion on the circuit being measured.

6. ### Colin Mitchell

1,417
312
Aug 31, 2014
"The misunderstanding comes from a wrong interpretation of the meter's ratings. If can measure either up to 10A or up to 1000V. But not both simultaneously."
NO.
Basically the meter has insulated leads and you can measure either AC or DC up to 10 amp on a 1,000 volt line.
"At 1000V there will be a very small current (a few µA), "

At 1V there will also be a very small current (a few µA).

7. ### Harald KappModeratorModerator

10,383
2,267
Nov 17, 2011
Yes, you can, but you still measure either current or voltage, not both simultaneously.

8. ### Martaine2005

2,933
800
May 12, 2015
I personally wouldn't put that meter anywhere near 10A or 1000v.
the meter is cat111 600v. I would guess that's it's absolute maximum.
And only just got cat 111 by the skin of it's teeth.

youtube has many videos testing meters and Fluke tested 100's of Japanese meters. They all blew to pieces and caught fire.

If you want to play with high voltage and high amps, buy a dedicated tester.
And use your multimeter for home projects only.

Martin

Harald Kapp and davenn like this.
9. ### davennModerator

13,654
1,888
Sep 5, 2009
agreed Martin !!
a very wise response

10. ### AnalogKid

2,393
665
Jun 10, 2015
You are combining two different specifications of the meter incorrectly. The 10 A rating is the maximum current the meter can sense without damage when acting as a current meter. The 1000V rating is the maximum voltage the meter can sense without damage when acting as a volt meter. The meter can be in one measurement mode or the other, never both at the same time; it cannot measure both things at once - that would be a power meter, a very different device.

ak

11. ### cjdelphi

1,096
104
Oct 26, 2011
Current is what causes the fuse to blow, simply heat melts the fuse... for example to blow a 1amp fuse, you could use 1 aa battery and short it and blow it...

but you could equally use 1000v but only 1ma and while very deadly, that fuse should not blow...

amps x volts = watts

Total power is measured in watts

12. ### Minder

3,007
640
Apr 24, 2015
For my Fluke multi-meter I use the AC/DC Clamp on ammeter accessory, high range and no exposure to high voltage.
M.

13. ### cjdelphi

1,096
104
Oct 26, 2011
I bet a lot of "experienced" electronics guys have been hit with high voltage a few times in their life

14. ### Martaine2005

2,933
800
May 12, 2015
<<------- And 'inexperienced'