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M9005 • REV N
(May 2017) Page
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b) Verify current output with separate current meter connected in series with the 4-20 mA
output and the receiving instrument input. Verify the current is correct. Current output with
zero vibration should be 4.0 mA. A 20 mA current represents full scale vibration.
3. The unit does not respond to a vibration input during the first few seconds of operation.
a) The startup time delay circuit prevents the transmitter from reacting to a vibration input
during the startup delay time period. The standard time delay is fixed at 30 seconds. If the
unit has the optional variable startup delay, it can be varied from 1 to 30 seconds. The cur
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rent output is held at 4.0 mA and the display is held at 000 until the startup time delay has
expired.
4. The unit trips the limits shortly after applying power to the unit.
a) Units with an adjustable startup time delay which is set close to the minimum setting can
have the limits trip at power up. This is due to the settling time of the circuitry in the Model
SW6000 switch. If a short startup delay is desired, it is suggested that power first be applied
to the unit for a minimum of 20 seconds. Power may also be applied continuously. The limits
may need to be reset depending on the particular application. Afterwards, the machine can
be started in a normal fashion.
5. The unit is functioning but accuracy is in question.
a) The vibration output can be verified by placing a separate vibration pickup near the base
of the Model SW6000 and comparing the two readings. Remember that the vibration meter
or analyzer must utilize true RMS detection and have similar frequency response character
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istics. Even then, significant differences can exist due to dissimilar sensor orientations, hand
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held versus rigid mounting, meter or analyzer time constant differences, and other factors.
The calibration of the Model SW6000 should be verified on a yearly basis as a minimum.
b) Alternately, the unit can be removed and placed on a calibrated shaker system in order to
verify the calibration. Metrix Instrument Co. can provide factory calibration traceable to NIST
standards.
6. The unit does not appear to be functioning.
a) Ensure that all wiring connections to the terminal block are correct, terminal screws are
tight and that the correct voltage is present at the terminal block power (Vin) terminals. DC
voltage polarity is arbitrary. Refer to Figure 4 and Product Identification page 2 for specific
details. If power is applied, the LCD display (if present) should be functioning, and the cur
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rent output should be between 4.0 and 20.0 mA.
