Tech Note 314 Detail

Measurement of ouput voltage on 1000 V setting reads 10 times too low.

Affected Products:

ES-9049A Power Supply

If one places a standard digitial multimeter on the output, one reads values that are only one tenth of those alleged by the ES-9049A.

PASCO Solution:

The unit is working fine: A standard digital voltage meter has a input impedance of only 10 MOhms. In most cases, this impedance is sufficiently high that the meter correctly reads the unloaded output voltage; however, for safety reasons, the ES-9049A has an output impedance of 100 MOhm.

This means that a standard digital voltage meter will read only 1/10 of the unloaded output value.
If you are in doubt of the accuracy of the high voltage output and would like a direct measurment of the output voltage, you will need to use a probe with an input impedance of 1 Gigaohm or greater.

Creation Date: 02/8/2002
Last Modified: 02/5/2004
Mod Summary: