Dynasonics D300_301 Series Doppler Ultrasonic Flow Meter - Manual (Page 24)

Rev. 2/00 -4.5- 300/301
the Fluid Sound Speed Compensation chart located
in the Appendix of this manual.
Once a new calibration frequency has been
determined, the frequency is input as a 1 Vpp sine-
wave into TP3 on the main circuit card. This input will
simulate full scale flow in the circuit. With the function
generator inputting the calibration frequency the
SPAN, 1mA, 20mA and CTR inputs can be
configured. A 10% and 50% of SPAN frequency can
be input and flow meter linearity can be verified.
Noise and Gain Adjust
If meter indicates a reading with no flow, turn R10
(GAIN) C.C.W. just enough to eliminate. Since this
reduces sensitivity, do not turn past point of proper
operation. If indicator will not read flow, turn R10
(GAIN) C.W.
Relay Adjustment
1. Turn R80 (DLY) fully CCW for minimum delay (2
sec.) before proceeding with alarm trip
adjustments.
2. For a point of reference, turn R70 (ALM) also fully
CCW.
3. At the desired flow dropout (which can be
simulated by the procedure covered in the
Electronic Calibration Procedure on Page 4.4),
slowly (due to time delay) adjust alarm R70 (ALM)
CW until relay is deactivated. Do not overturn.
NOTE: About 10% flow hysteresis is built-in into
the flow switch system at 1 FPS.
4. After a desired alarm trip point is established,
adjust R80 (DLY) CW for a desired time delay (20
sec. Max. On flow dropouts).
PART 4 - CONFIGURATION AND OPERATION