PGA300: PGA300

Hi Ed,

Do you have an example of the collected ADC data and calculated coefficients for the first and second calibrations? Do you keep the same analog and digital EEPROM settings between each calibration, or do you have to adjust something to make the second calibration accurate?

Regards,
Scott

Hello Scott,

For example, first time calibration of 0-50-100psi, the result was 0-45-82psi, I changed nothing, just recalibrated 0-50-100psi PADC HEX second time, the result back to 0-50-100. BTW, I use Register not FIFO. Thanks!

Ed

Hi Ed,

Can you share the ADC readings that you took during the calibration on both tries?

Thank you,
Scott

Hi Scott,

Before calibration, I "stretched" detector from 0 to 1000 psi.

• First calibration (0/500/1000psi, T-HEX:2685)

            FFCA/6F2/E27 = 0/463.9/962.6psi

• Second calibration (0/500/1000psi, T-HEX: 2688)

             FF43/66E/D9F = 0.1/500.3/999.8psi

Thanks!

Ed

Hi Ed,

Is this behavior repeatable across several different samples? Do you use the same pressure sensor, or a different one each time you test?

It looks like over time the sensor is somehow providing different outputs for the same pressure. I would measure the output of the pressure sensor directly with a voltmeter during each calibration and each verification of the results.

Regards,

Scott

Hi Scott,

we changed nothing and just redo PADC, this was repeatable to this particular calibration workstation all the time. 

The HEX difference between first calibration and second calibration is consistent 87!

at 0psi: FFCA-FF43=87

at 500psi: 6F2-66E=86

at 1000psi: E27-D9F=87

we just test another 1000psi  transducer, the delta between first and second time is consistent 302 (hex)

Thanks! 

Hi Ed,

That's very interesting. If you move the transducer from one PGA300 to another, does it still take 2 calibrations before it is correct? 

Regards,

Scott