Dynasonics DDFXD Doppler Ultrasonic Flow Meter - Manual (Page 52)

52 06-DPP-UM-00147 02/12
Symptom Resolution
Rate Pulse output does
not match data collection
system
1. Verify 0 Hz and MAX Hz flow settings
2. Place oscilloscope or frequency counter on the Rate Pulse module
outputs and verify frequency output
3. Run output TEST feature – verify that the Hz output coincides with
expected data collection system readings
4. Verify that “K-factor” has been calculated correctly:
K-factor = Hz/(flow/second)
Example:
Max Hz (2,500 Hz) = 10,000 Gallons/Minute
K-factor = 2,500 Hz / 166.7 Gallons/Second
K-factor = 15 pulses/gallon
5. Verify that the data collection system is accepting the pulses from the
DFX – connect to Turbine out or OUT/IN as required
DFX does not capture short
flow pulses
1. When run in AUTO mode, the DFX utilizes a series of filters that op-
timize readings for a particular flow range. The flow meter will take
several seconds to adjust to a step change in flow. To make the flow
meter respond quickly to changes in flow, decrease DAMPING, place
the meter into MANUAL AGC and lock the FILTER at NONE.