Dynasonics DDFXD Doppler Ultrasonic Flow Meter - Manual (Page 48)

48 06-DPP-UM-00147 02/12
GAIN CONTROL
GAIN POT – DIGITAL GAIN POT
0-64
Using the arrow keys, increase or decrease the numerical value to set the signal gain level. Typically, opti-
mum flow measurement is made when this value is between 10 and 50. Use the lowest value that pro-
vides an accurate and stable flow reading. This adjustment must be made in conjunction with the FILTER
setting, and may be an iterative process.
HARDWARE FILTER
FILTER – HARDWARE FILTER SELECTION
NONE - No Filter
LOW - (1600 Hz Cutoff)
MEDIUM - (350 Hz Cutoff)
HIGH - (250 Hz Cutoff)
Select the hardware filter with a cutoff frequency that is above the Doppler shift frequency to be mea-
sured. The Doppler shift frequency is found by multiplying the flow velocity (in FPS) by 80.
For example, if the flow velocity is 4 FPS then the cutoff frequency is 4 × 80 or 320 Hz. The filter with the
next highest frequency would be 350 Hz.
TRANSDUCER TYPE
XDCR TYPE – TRANSDUCER TYPE
DT9 - Clamp-on Transducers
PROBE - DP7 Insertion Probe Transducer
Select the appropriate transducer type to be connected to the DFX transmitter. The selection invokes
optimum hardware and software settings unique to the transducer architecture.
CORRECTION FACTOR
C FACTOR – TRANSDUCER TYPE
0.01 - 5.00
This value is established at the factory during calibration. If a new set of transducers or insertion probe is
connected , the new correction factor should be entered. The correction factor values can be found on
transducers or probes labels.