Question 1

The stated accuracy for DC current is, " +/- 2.5% +/- 10 dgts."   (Assume "dgts" = digits?)   Can anyone clearly explain what "+/- 10 digits" means?

Accepted Answer

The +/- 10 digits means that the meter may be off 10 digits in the least significant (furthest to the right of the decimal place) digit. It's a standard way that meters are rated for accuracy besides the +/- %. If the meter is reading to 3 significant digits (0.000 to +/- 9.999 then the meter may be "off" ten digits in the 0.00x place). This is in addition to the percent error. For example, if this meter reads "1.000" mA. The actual value may be +/- 2.5% (+/- 0.025 mA) +/- 10 digits, so that means the actual value would be between 1.000+/-.025+/-.010= 1.035 to 0.965. If the meter range was only 2 decimal places (it read 1.00) then the actual value would be 1.00+/-.025+/-0.10= 1.33 to 0.87. Think of "+/- digits" at the amount number of values the least significant digit in the reading may be "wrong". This must be added to the percentage error. Hope that makes sense.

Question 2

Will the 100 amp max. range be enough to check the starter current drawn from the battery by cars & trucks ? Will the clamps fully grip the cables ?

Accepted Answer

For starter motors, this is the wrong tool for the job. It is the best low current clamp meter I have used, closest measurement to a Siemens device I also use, and that's well over $3000.

This little guy fits in your pocket, and it's made in the USA.

It is temperature sensitive, so it does require zeroing occasionally, its only drawback. But, if you are measuring a few milliamps, it's very useful.

For starter draw, I use the Fluke 88 with the i1010 clamp accessory. With this device, you can read average and peak draw.

Question 3

For AC current measurements at the low end (20-100 mA), does this meter achieve the stated accuracy/precision (+/- 10 mA)?  Thanks.

Accepted Answer

On AC current it is OK but on DC it is very unstable and you have to constantly pushing Reset because after measuring a current it does not returns to zero, it stays at there last measure.

Question 4

Can this meter read in the 2 - 3 ma range in the ac mode?

Accepted Answer

I never try that, for low frequency should be OK. For high frequency AC , should use scope.

ASIN	B001TCWL1E
Best Sellers Rank	#328,742 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #197 in Clamp Meters
Brand	GTC
Brand Name	GTC
Color	Grey with Yellow Clamp
Customer Reviews	4.4 out of 5 stars 302 Reviews
Global Trade Identification Number	00833303000282
Included Components	CM100, 2 batteries, User's manual, Test leads, Soft carrying pouch
Item Dimensions	11.4 x 5.7 x 2.5 inches
Item Type Name	Current Clamp Meter
Item Weight	0.95 Pounds
Item dimensions L x W x H	11.4 x 5.7 x 2.5 inches
Manufacturer	General Technologies Corp.
Measurement Type	Ammeter
Model	CM100
Part Number	CM100
Power Source	Battery Powered
Specification Met	Gtc
Style	Modern
Style Name	Modern
UPC	833303000282
Unit Count	1.0 Count
Warranty Description	1 YEAR EXCLUDING BATTERIES

GTC CM100 1 mA to 100 Amps AC/DC Low Current Clamp Meter by General Technologies Corp

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