Instantel 716A0401, Руководство оператора

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Reference
MiniMate Plus Operator Manual
5–7
c. Transducer Calibration Requirements
The geophone sensors inside the MiniMate Plus and inside Instantel’s transducers must be
calibrated annually by Instantel or an authorized Instantel service facility. Contact your dealer for
further information.
5.2.2. Microphone
The microphone measures air pressure. Instantel offers two types: Linear “L” (standard) and “A”
Weight (optional). Both come with a three foot (one meter) microphone mounting stand.
a. Measurement Scales
The MiniMate Plus supports two sound pressure measurement scales: Linear “L” and “A”
Weight.
(1) Linear “L”
Linear measurement is generally used to measure the effect of low frequency air pressure on
buildings. The linear scale records sound pressure without modification in the 2 to 300 Hz range.
Measurement units may be in absolute, Pascal, or relative dB scales.
(2) Weight
“A” weight measures noise levels people may consider an annoyance. The signal is then
converted to root mean square (RMS). Units are measured using the decibel scale, dB(A).
b. Microphone Calibration Requirements
Instantel’s microphone must be calibrated annually by Instantel or an authorized Instantel service
facility. Contact your dealer for further information.
5.3. Sensorcheck
Sensorcheck performs a two stage test on the MiniMate Plus and its sensors. In the first stage, the
program displays the MiniMate Plus serial number, software version, the total amount of memory
installed in the MiniMate Plus, the total amount of memory available to store events, and the
number of events presently stored in memory. The second stage tests each geophone within
Instantel’s transducer and the microphone operation. The program also tests the operation of the
MiniMate Plus itself and the sensor connecting cables. Pass or fail results appear on the display.
See the Basic Reference chapter of this manual to choose when Sensorcheck operates
automatically.
5.3.1. Checking the Transducer’s Geophones
Sensorcheck measures a geophone’s natural frequency and damping indicated by an Overswing
Ratio (OR). Sensorcheck sends an electric pulse to the geophones and measures the response. If
the geophone’s response falls within a specified calibration range, the geophone is in calibration
and monitoring operations can continue. If the geophone’s response does not fall within a
specified calibration range, the geophone is not calibrated. You cannot record events until you fix
or replace the geophones. See the troubleshooting section of this manual for the appropriate
procedures to follow.
a. Natural Frequency
Waveform measurements check the natural period (t) of a geophone’s sensor coil assembly.
Referring to the figure below, the distance from P
1
to P
2
represents 0.125 seconds. Since
Frequency is the reciprocal of the period, F=1/t, the frequency is approximately 8 Hz. A calibrated