PicoScope 7 Software
Available on Windows, Mac and Linux
Understanding Picoscope calibration certificate
Understanding Picoscope calibration certificate
I am trying to work out the accuracy of the Picoscope from the calibration certificate.
Can you please explain the following entry in the calibration certificate?
DCGain_5V_90%_12bit_1M (what does 1M mean?)
Nominal 4.50
Lower 4.4230 (lower limit given by the accuracy spec?)
Upper 4.5770 (upper limit given by the accuracy spec?)
ChA 4.4929
ChB 4.5097
TUR 220.9:1 (what does this mean?)
Max % spec 12.6% (maximum tolerance given by spec?)
Can you please explain the following entry in the calibration certificate?
DCGain_5V_90%_12bit_1M (what does 1M mean?)
Nominal 4.50
Lower 4.4230 (lower limit given by the accuracy spec?)
Upper 4.5770 (upper limit given by the accuracy spec?)
ChA 4.4929
ChB 4.5097
TUR 220.9:1 (what does this mean?)
Max % spec 12.6% (maximum tolerance given by spec?)
Re: Understanding Picoscope calibration certificate
Hi santander,
To answer your questions:
1M is the input impedance of the PiocScope Channel in ohms.
The 'Nominal' value is the value expected to be measured (in the case of DCGain of 5V at 90%, the Nominal value would be 4.50 V)
'Lower' refers to the Lower tolerance limit according to the specification and measurement uncertainty being applied.
'ChA 0.0390625' is the actual measurement result from calibration.
'TUR', i.e. 'Test Uncertainty Ratio' is the uncertainty of the parameter being measured for the device being calibrated, relative to the total uncertainty being contributed to the result by the Measurement Process. So, a TUR of 220.9:1 means that the parameter of the device being measured has a very large uncertainty (very low accuracy) when compared to the uncertainty of how it is being measure (i.e. when compared to the uncertainties for the device being used for calibration, along with the measurement process, environment etc), which means that the action of performing the measurement contributes negligible error to the measurement results.
'Max % Spec' is the Maximum deviation of a measured value for any of the Channels, as a percentage of the permitted range of variation defined by the relevant Test Limit (Lower or Upper). So, for instance, if Channel C had the Maximum +ve deviation from the Expected value, it would be calculated as:
(Measured value for Channel C - Nominal value) * 100
(Upper Limit - Nominal value)
Regards,
Gerry
To answer your questions:
1M is the input impedance of the PiocScope Channel in ohms.
The 'Nominal' value is the value expected to be measured (in the case of DCGain of 5V at 90%, the Nominal value would be 4.50 V)
'Lower' refers to the Lower tolerance limit according to the specification and measurement uncertainty being applied.
'ChA 0.0390625' is the actual measurement result from calibration.
'TUR', i.e. 'Test Uncertainty Ratio' is the uncertainty of the parameter being measured for the device being calibrated, relative to the total uncertainty being contributed to the result by the Measurement Process. So, a TUR of 220.9:1 means that the parameter of the device being measured has a very large uncertainty (very low accuracy) when compared to the uncertainty of how it is being measure (i.e. when compared to the uncertainties for the device being used for calibration, along with the measurement process, environment etc), which means that the action of performing the measurement contributes negligible error to the measurement results.
'Max % Spec' is the Maximum deviation of a measured value for any of the Channels, as a percentage of the permitted range of variation defined by the relevant Test Limit (Lower or Upper). So, for instance, if Channel C had the Maximum +ve deviation from the Expected value, it would be calculated as:
(Measured value for Channel C - Nominal value) * 100
(Upper Limit - Nominal value)
Regards,
Gerry
Gerry
Technical Specialist
Technical Specialist