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U327_UFAUVALDG16_B_e_170808
7 Functional Description
UFA transducers are designed for connecting to vane wheel probes FA and FAR (directional sensing) and
vane wheel measuring tubes FA Di and FAR Di (directional sensing) for measuring flow velocity or flow
rate of air/gases and water/liquids.
UVA transducers are designed for connecting to vortex probes VA and vortex measuring tubes VA Di for
measuring the flow velocity or flow rate of air/gases.
The signal frequency proportional to the velocity generated from the flow sensor is converted to a linear
analog output signal 4-20 mA or 0-10 V. The analog terminal value is configurable. When logging direc-
tional sensing data the zero point can be selected in the middle of the analog range or directional sensing
takes place with the help of the relay output:
for FA and FAR*: 4 ... 20 mA
= 0 ... x m/s (or m³/h)
for FAR: 4 ... 12 ... 20 mA
= -x ... 0...+x m/s (or m³/h)
for VA: 4 ... 20 mA
= 0 ... x m/s (or m³/h)
alternatively:
for FA and FAR*: 0 ... 10 V
= 0 ... x m/s (or m³/h)
for FAR: 0 ... 5 ... 10 V
= -x ... 0...+x m/s (or m³/h)
for VA: 0 ... 10 V
= 0 ... x m/s (or m³/h)
* for FAR sensors for configuring the relay see under: ±direction of flow
The actual velocity or actual flow rate can be converted to standard velocity or standard flow rate by en-
tering the parameter for temperature and pressure.
A relay output (change-over contact) can be configured for 1 of 3 different functions:
1. as limit value for the flow velocity or the flow rate:
flow velocity < or = limit value: relay contact idle
flow velocity > limit value: relay contact in working position
2. as quantity pulse for quantity measurement:
max. pulse repetition frequency 1 Hz per unit of volume,
configurable, e.g. 1 pulse per 1, 10 or 100 (norm)-m³ or (norm)-litre
pulse duration 0.1 s (FAR sensors: configurable for '+' or '-' amounts)
3. as ±direction of flow ** (for FAR sensors only):
+direction: relay contact in idle
- direction: relay contact in in working position
** analog output (see above) is then absolute value of flow only, without direction
Self diagnosis according to NAMUR NE43:
No error:
yellow LED off
green LED on (flow velocity = 0) or
green LED flashes (flow velocity > 0)
Error:
yellow LED on and with
- analog output 4-20 mA : < 3.6 mA
- analog output 0-10 V
: < -0.2 V
Monitored: power supply, data logging, sensor interface, parameter settings (see under 16: Trouble-
shooting)
PC serial port RS232:
for changing calibration data and setting parameters.
Remove front cover (see Fig. 1)
Plug PC connector cable (optional) with RJ22 into the socket in the transducer (see Fig. 2).
Connect other end of cable to PC COM port.
If a USB connection is required, then an optional USB / RS232 interface converter must be inserted.
Changes to the settings can now take place after starting the PC programme UCOM (optional)
(see under 8: Settings).
