DVM measuring method

[davew]

I'm working at a univercity where were're teaching electronics and
I want to find out how DVMs particulary the standard type we use[1]
measure their values and achieve the accuracy stated.

Do they use the wheatstone bridge method or is there another method
with modern digital meters.

Thanks for any help or pointers to help/info



[1] Ours are mostly Black Star 3 1/2 digit nothing expensive just basicspec
meter.

 

[Andrew Tweddle]

davew wrote:

I'm working at a univercity where were're teaching electronics and
I want to find out how DVMs particulary the standard type we use[1]
measure their values and achieve the accuracy stated.

Do they use the wheatstone bridge method or is there another method
with modern digital meters.

Thanks for any help or pointers to help/info



[1] Ours are mostly Black Star 3 1/2 digit nothing expensive just basicspec
meter.


Go to

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3706

for a short description of these IC's

regards Andrew

 

[Robert Baer]

davew wrote:

I'm working at a univercity where were're teaching electronics and
I want to find out how DVMs particulary the standard type we use[1]
measure their values and achieve the accuracy stated.

Do they use the wheatstone bridge method or is there another method
with modern digital meters.

Thanks for any help or pointers to help/info

[1] Ours are mostly Black Star 3 1/2 digit nothing expensive just basicspec
meter.

Youse no engrish?

 

[John Miles]

In article <ch1nuv$qvg$1@beta.qmul.ac.uk>, davew@elec.qmul.ac.uk says...

I'm working at a univercity where were're teaching electronics and
I want to find out how DVMs particulary the standard type we use[1]
measure their values and achieve the accuracy stated.

Do they use the wheatstone bridge method or is there another method
with modern digital meters.

Thanks for any help or pointers to help/info



[1] Ours are mostly Black Star 3 1/2 digit nothing expensive just basicspec
meter.

You can download the service guide for the HP 34401A DMM (a very popular
lab-grade model) at http://cp.literature.agilent.com/litweb/pdf/34401-
90013.pdf (160 pages, 12 MB). HP service manuals generally make
excellent tutorials.

Short answer: no, direct A-D conversion is the usual measurement
technique in commercial meters. Certain RF instruments use the
Wheatstone Bridge principle to deal with complex impedances, but it's
not widespread elsewhere.

-- jm

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