5.
Repeat step 4 for all other frequencies until 10 Hz (9 kHz, 8 kHz, 7 kHz, 6 kHz, 5 kHz, 4 kHz, 3 kHz, 2 kHz,
1 kHz, 500 Hz, 300 Hz, 160 Hz, 100 Hz, 50 Hz and 30 Hz). Record the volt meter reading, displayed
amplitude and displayed sensitivity (if testing HI-913) in the corresponding row in the workbook for each
frequency.
6.
Before testing at 10 Hz and below, set the volt meter filter to slow if possible. Or in lieu of this use the
averaging feature on the volt meter to get a stable reading.
a.
Metrix uses Agilent model 34401A
6.5 digit digital volt meters when testing
portable shakers. To set the filter to slow:
i. Press Shift then on/off
ii. Press the down arrow twice
iii. Press the < arrow, display will
read “Slow: 3 Hz”
iv. Press Auto/Man (Enter) to save
changes
7.
Set the frequency of the portable vibration calibrator
to 10 Hz. 1.0 g pk is not possible at this speed, use
lower amplitude such as 0.8 g’s pk. Record the volt
meter reading and displayed amplitude in the corresponding row in the workbook for each frequency.
8.
Repeat step 7 for 7 Hz using 0.4 g’s pk for the amplitude.
a.
Note: if using a calibrator with 9100-LF5 firmware, repeat step 6 at 5 Hz as well using 0.2 g’s pk as
the amplitude.
Reviewing the Test
The Field Validation Workbook will calculate the measured PVC amplitude and % difference between
known amplitude and measured. Once the % difference is calculated the cell turns green, yellow or red:
Green cell: indicates the tested value passes specification for accuracy
Yellow cell: indicates the tested value passes specification for accuracy but is more inaccurate than typical
Red cell: indicates the tested value is outside the acceptable error bounds per specification
For test points with “yellow” or “red” indication Metrix recommends checking the mounting of the
accelerometer and re-testing. Clean the armature surface, re-apply silicone grease and re-torque the
sensor. Then test again to be sure shaker is inaccurate. If problems persist, contact Metrix. The portable
vibration calibrator may need to be adjusted, although adjustments are very rare due to the stability of the
device’s quartz reference accelerometer.
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