Author Topic: Datron 1081 Teardown and repair  (Read 3963 times)

0 Members and 1 Guest are viewing this topic.

Offline MaxFrister

  • Regular Contributor
  • *
  • Posts: 78
  • Country: 00
  • Country: 00
Re: Datron 1081 Teardown and repair
« Reply #50 on: June 15, 2019, 10:04:34 pm »
Good ideas.  I've been focused on getting the meter working and so I have not spent much time calibrating.  I've done most of the digital board adjustments but I skipped over reset signal.  I'll go back and check that one.

I think it is possible that the calibration constants were okay but not being read correctly over the bus.   Of course once I pulled the ics that was no longer true.

I have no idea what to make of the noise on the long logging run.  It correlates with the HP meter so it may be external to the Datron.  There seem to me to be 3 possibilities: source reference noise, AC power problems, or external EMI. 

As for EMI, I am in range of a couple of military installations and they have been known to take out the local cable TV.  As the US is prepping for war with China, Mexico, North Korea, Canada, Iran, and/or Australia who knows what they are doing this week.

I'll setup both meters to read a shorted voltage tonight.  That will take the voltage reference out of the equation and disconnect the 2 machines from each other.
« Last Edit: June 15, 2019, 10:14:55 pm by MaxFrister »
 

Offline MaxFrister

  • Regular Contributor
  • *
  • Posts: 78
  • Country: 00
  • Country: 00
Re: Datron 1081 Teardown and repair
« Reply #51 on: June 16, 2019, 01:50:58 pm »
The overnight logging of shorted meter inputs is much prettier.    There is only minor deviation with temperature and no 50ppm excursions.   I still don’t know what that happened in the previous run.  I’ll set it up to run that experiment again.

For the Datron, the settings are “F3R4T2C1A3” with a side of “K1L5”.  That translates to DCV, 10V range, normal triggering, low-pass filter on, and block averaging with the block size set explicitly to 1.

The temperature sensor is programmed to behave like a GPIB instrument so it is trivial to use here.   The sensor is a Dallas 1-wire sensor.  I have a fancier BME280 sensor but I can’t seem to find it.  Somehow I never lose the boat-anchor instruments.

I’ve attached the logging script.  It is about as simple and dumb as can be. 

 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf