The HFM Flowmeter is a non-invasive device utilizing the frequency shift (Doppler effect) of a signal to measure the flow velocities of liquids. The transmitters feed a high frequence voltage to transmitter crystal of the transducer. The crystal converts the voltage to a high frequency mechanical signal which is projected through the wall of the pipe and into the liquid. The signals are reflected back to a receiver crystal by the discontinuities in the fluid. The frequency difference between the transmitted and received signal is directly proportional to the fluid's flow velocity. In order to receive an adequate frequency shift, the liquid must contain reflective particles such as air bubbles, minute particles or other well-defined discontinuities.
The normal fields of application are where conventional flowmeters do not work or create problems. Doppler flowmeters are usually more cost-effective in that they do not vary in price with an increase in pipe size. These instruments normally require no change in the piping system and installation is fast and inexpensive.
|Flow Range||0.3 to 6 m/sec. - 0.5 to 20 ft/sec.||0.5 to 20 ft/sec. and GPM|
|Accuracy||Digital readout: ±2.0 L.S.
Repeatability: ±0.2% (F.S. range)
Linearity: ±0.5% (F.S. range)
Resolution: 0.1 m/sec
|Power||5 VDC, supplied by internal nickel-cadmium batteries (or Charger below)|
|Transducer||Dual crystal hinged for ease of alignment|
|Operating Temperature||Electronics -25°C to 85°C
Transducer -40°C to 150°C
|Readout||12.5m LCD display with low battery indicator|
|Analog Output||N/A||4 to 20 mA. DC||N/A|
|Size||7.5" long x 4.25" wide x 2" deep|
|Weight||1.8 kilograms /4 lbs.|
|Chargers||2 styles available|
|Case||Padded nylon case holds flowmeter, transducer, interconnecting cables, couplant & charger.|
|AUHFM-1000||HFM-1 Flow Meter|
|AUHFM-2000||HFM-2 Flow Meter with 4-20mA output|
|AUHFM-4000||HFM-4 Flow Meter with range of 0.5 to 20 ft./sec and GPM|