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Abstract:
Monitoring a transducers’ Bias Output Voltage (BOV) can help pinpoint bad
cables, failed sensors, and ensure proper sensor operation. Many on-line systems have
the capability of trending this value to help maintain data integrity. The intent of this
article is to illustrate the proper set-up for such measurements within Emonitor Odyssey
and the enWATCH unit. Since this measurement is extracted from the Multiplexer, or
“MUX” of the enWATCH unit per each pickup, there is no need for a separate DC
coupled input type or “waste” of another channel. Likewise, There are NO additional
hardware configurations necessary.
The following illustrations depict proper setup:
enWATCH Application Note (cont’d)
A new transducer must be defined prior to setting up the proper “Collection
Specification” for the measurement. This can be accomplished by selecting
“SETUP/Transducers..” from the main menu of Emonitor Odyssey, and then adding a
NEW transducer with base units of Voltage. *See Figure below.
After setting up the new transducer you must define the Calibration value for the
enWATCH unit. This can be accomplished by selecting “SETUP/Calibration...” from
the main menu of Emonitor Odyssey. “Bias Voltage” should be selected as the input type
with units of Vdc and Calibration value of 1000.
enWATCH Application Note (cont’d)
The Collection Specification for the Measurement can be defined as follows.
Select “SETUP/Collection...” from the main menu of Emonitor Odyssey, and Choose
NEW or Copy the existing “VOLTS DC” specification for reference.
After these items have been completed the measurement may then be loaded to
the enWATCH unit. As an additional note, there may be slight variation in the measured
voltage on the unit (taken with Multi-meter) verses what is stored in Emonitor Odyssey.
Typically a +/-5% variation in the values may be expected due to scaling and resolution.
These values can be trended and correlate to the actual voltage. An example follows:
Reading stored in Emonitor Odyssey: 9.02 vDC
Reading taken on unit with Multi-meter: 8.51 vDC
Further information regarding this Application Note or measurement setup can be
obtained from EntekIRD International. Please call the Customer Support Hotline number
at 1-800-369-3547 or email to [email protected].