CALIBRATION OF DIGITAL MULTIMETER
please provide information about ” how to calibrate digital multimeter / megger / clamp meter using multi fuction calibrater. Also give a sample calibration sheet
I beg to differ on the above opinion that most modern multimeters do not require calibration. Most DMM’s produced within the recent past have one of two methods of adjustment. Either series of potentiometer adjustments or electronic adjustments. Both of these can and typically will drift out of tolerance with time due to a variety of different factors. The only time (that I could see) where you wouldn’t need a meter calibrated is for basic troubleshooting i.e. there is about 120VAC at the outlet or a fuse is or isn’t blown.
Exactly how to calibrate your digital multimeter / megger / or clamp meter can depend on the internal design of the instrument. You would calibrate the instrument by verifying the meter’s accuracy against a traceable power source or meter calibrator such as a Fluke 5700A. Typically you will check the multimeter as several test points through out one of the meter’s ranges to verify scale linearity. As well as one point at near full scale in all other ranges and functions.
Josh
http://www.appmet.com/
Most modern digital multimeters do not require calibration except in the most detailed and precision work. There are some that do. Here is an example of the manual for a Keithley Model 2000 Multimeter Calibration Manual –
http://idtl.stsci.edu/products/manuals/Keithley%20manuals/2000_905_01D.pdf
It was posted on the website for the Johns Hopkins University Independent Testing Laboratory Website.
It provides you the detailed procedures for calibrating that unit. The procedures could be easily adapted to other devices.
Recognize that many modern devices can not be really calibrated but calibration / correction curves can be developed using similar procedures.
Niel
