About multimeter.

On July 28, 2011, in Electronics, Misc, by Cmc

As I began with my engineering path I had practically no money or tools. First thing that any one involved in electronics design needs is a multimeter.  Since I was just poor student, I needed to get what I could as cheap as possible.

I got this:

Image from the internet that looks exactly like my ex-multimeter.

This is actually one of those 10$ multimeters. It was reasonably good on measuring resistance and I believed that voltage is at range. Until I needed to use 2 multimeters at once. I found out that my multimeter is not accurate. It actually showed different offset at every voltage. I got offsets starting from -3V ending at +5V.

So, I was thinking, that is not right…  I brought out my breadboard and set up LM7805 regulator to see what voltages I would get. You guessed right. Second device was nicely in range and multimeter was showing random number. It was actually off by -1.5V.

NO SHIT I cant find problem in my design if I tune it with that multimeter!

I was enraged!

 

Lastrly I even tried to calibrate the multimeter internally but it was of no use. I could make voltage lower or higher but it still was non linear offset.

I was so pissed that I just went out and ordered proper multimeter. Now I am a proud owner of Agilent U1231A.

This is my first proper multimeter!

It is missing the current measuring capability but I am poor student. I figured that I am going to need second multimeter any way so I might as well keep few bucks and buy first one without Current measuring capability. When I am going to need current measuring capability I just have to buy second meter. As I have never had any need for that yet I guess I can survive few more months and get second meter for Christmas or something. At the moment it seems that I need 2 voltages much more.

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