ZES ZIMMER LMG450, Руководство пользователя

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Miscellaneous LMG450
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First the signal has to be divided into its frequency components. Then the errors of the rms-
values of each frequency component have to be calculated. The used error is the standard error
of reading at the specific frequency according to the technical specification. All these errors
have to be added geometrically (because they are rms values with different frequencies).
Further on you have to add the error of the measuring range of the fundamental once (once
because it includes common errors like offset, ...). With this sum you can calculate the total
error.
The values in the columns of the following table are:
Frequency (f / Hz)
rms value at this frequency (U / V)
Percentage error of frequency component according to technical data (% of value)
•
Absolute error of frequency component (
∆
U / mV)
f / Hz U / V Error in % of U
Error
∆
U / mV
100 4.501 0.1 4.501
300 1.500 0.1 1.500
500 0.900 0.1 0.900
700 0.636 0.1 0.636
900 0.499 0.1 0.499
1100 0.408 0.2 0.816
1300 0.346 0.2 0.692
1500 0.300 0.2 0.600
For this example only the harmonics from 1 (100Hz) to 15 (1500Hz) have been used.
Harmonics of a higher order cause just barely greater errors not affecting the total error very
much like shown in the table.
The geometrical sum of all errors results in an error of 5.05mV.
To that you have to add the error of the range (0.1% of 12.5V (peak-value) = 12.5mV).
The total error is 17.55mV which is 0.35% of 5V.
12.2 Function fault
If you think you have found an error or function fault in a LMG450 please fill out the
following page and send it to ZES. If you think the measuring result are wrong, please also fill
out the second page. For this purpose connect the measuring circuit, freeze the screen with the
values and fill out the paper with the frozen values.