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Product : AT3600
Question : What is the accuracy of the frequency and voltage signal coming from the voltech unit? I have an example below of what I am looking for.
Would the frequency fall within the ± 1 kHz guideline?
If the Volt signal was set at 1Vrms would it go over that?
Is the fixture itself going to affect that much?
*The test frequency shall be 50kHz (± 1 kHz), sine wave at 1V (rms) max, 10mV min.*
Thanks in advance.
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Hi Bill,
Test Frequency Accuracy is 4Hz maximum at 50KHz from the following formula as shown in the user manual:
F <= 16kHz, error is +/-0.25Hz +/- 0.01% of requested frequency
F >16kHz and <= 250kHz, error is +/- 4Hz +/- 0.01% of requested frequency
F > 250kHz, error is +/- 64Hz +/- 0.01% of requested frequency
With regards to the voltage accuracy, if you set a 1V signal level exactly, then it could in fact be slightly higher than this due to the specification tolerance. The actual voltage accuracy depends on the test you are performing, but for all "low power" tests such as LS, Q, Z etc. then to calculate the specification, please use the AC and AV % specifications from the Z test: http://www.voltech.com/Articles/098-024/008/001/002/8_1_2_22_Z_AND_ZB_Test
The measured voltage level accuracy in % will always be better than the sum of AC and AV % errors in Z. At 1V, 50KHz, this comes to 0.165%. On top of this error, there's a "trim" level error which is how close the AT3600 will adjust the source to the programmed voltage. This allowed trim error depends on the programmed value for integration (Short, Medium or Long). If Short is chosen then it will trim to within 3%, otherwise 1% is used. For long integration then you would add the 1% to 0.165% to get 1.165%. If you want to make absolutely certain that the voltage is below 1V you should therefore program a signal level of 988mV. This is not normally done however because the tolerance involved will never make any difference to the readings taken.
I am sorry for the long and detailed answer but as always with these things they are never that simple! I will make sure that this voltage specification is added to a future version of the user manual. I hope it's clear, but feel free to ask me for any clarification.
Best regards,
Tim.
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