¿ªÔÆÌåÓý

  1. Test-Equipment-Design-Construction
  2. Messages
Single Messages Topics Expanded Polls

Re: Optimal full scale deflection on analog meters

 

On Fri, 19 Aug 2022 at 11:28, ray_g4lua via <raymond.gathergood=[email protected]> wrote:

Having used all kinds of multi-meters over a 50 year career, I have concluded that no matter where the range limits are set, you always come across a measurement that? falls around the overlap!
AVO are perhaps the best known manufacturer of analogue meters, back in the day. I have personally owned an AVO Multi-minor, an AVO Model 7, an AVO model 8 and a much rarer "AVO Test Set Multi Range No1" - the Mil Spec version of the AVO 8?(NATO part number 6625-99-105-7050).

The multi-minor, model 7 and Model 8 were all ranged as: 1.0, 2.5,10, 25... etc., up to?2500V FSD
The Test Set Multi Range No1 was different; it's ranges were 1.0, 3.0, 10, 30, 100... up to 3000V FSD

However, my thoughts are 1.0, 2.5, 5.0, 10, 25, 50... would be better; based on the fact the the best accuracy for an analogue meter is above 50% FSD.


Obviously if one has specific uses, then different scales would be useful.? But otherwise, I think if one wants N different full--scales between each decade, then they should be differ by a factor of 10^(1/(N-1)). So optimal values would theoretically be

1, 2.15, 4.64, 10.

To get above 50% of full scale, one would need to go insert another range

1, 1.78, 3.16, 5.62, 10

However, I think that lot would be pretty dam confusing. Could a human brain cope with

1, 1.8, 3.2, 5.6 and 10?

It might make the meter a bit messy, but would allow any reading to be over 50% of the scale.

73 de

Ray G4LUA

_._,_._,_

Dave?
Join [email protected] to automatically receive all group messages.