Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Accurate DC Voltage source reading  (Read 3426 times)
Guest

« on: August 30, 2001, 04:16:34 PM »

I have a Digital meter and I beleive the reading for voltages is off. Is there a way to connect
the meter to a source that is very accurate so that I can set the meter right?  My mind
escapes me as to what is accurate.    Bill
Logged
AC5E
Member

Posts: 3585




Ignore
« Reply #1 on: August 30, 2001, 06:22:54 PM »

Hi: Accuracy is relative, of course, but fresh dry cells are pretty close to identical.

  I checked a dozen brand new AA cells and found them to read between 1.567 and 1.571 volts. If yours measures a new and fresh AA at close to 1.57 your meter is close enough for any practical purpose.

  73 Pete Allen  AC5E

 
Logged
WB2WIK
Member

Posts: 21753




Ignore
« Reply #2 on: August 31, 2001, 06:56:02 PM »

Some ideas:

Check the anode voltage on your color TV set...a 32" tube has ~32,000V applied, just measure it.

Okay, I'm kidding!

Pete's suggestion is good, but beware that battery voltage varies with construction as we all know, and carbon-zinc, alkaline, mercury, Ni-Cd, NiMh, etc, etc, all have different cell voltages.  I've seen brand-new, factory-fresh Duracells (and similar) measure over 1.6V, so it might depend on the exact model and materials used in that particular production run.

Here's what I'd do (honestly): Take the meter to a local electronics store that sells reasonably good test equipment, along with a battery of some sort.  Use a store sample, something good, e.g., Fluke or whatever they have, and measure the battery.  Then use your meter to measure the battery.  If yours reads differently, it probably does need calibration!  

If you're really anal about this, or have some real, serious need for your DVM to be correct, you could always rent a voltage standard, or a piece of highly accurate test equipment (like a multi-thousand dollar professional DVM), from Electro-Rent or equivalent, and use that standard to calibrate your meter.  Professional test equipment rental typically costs 10% of the cost of the equipment, though, so renting a $1000 meter could cost $100.  Might be cheaper to toss it and buy a new one!

73 de Steve WB2WIK/6
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!