Product Manual

Wall Mounted Ultrasonic Flowmeter---User Manual

two methods above are also different. Generally, the result in the first method is smaller than that

from the second method.

1) With specific heat value method

While flow transducers installed on water supply pipe, the formulation is as below:

Instantaneous Heater rate qh=qV!pS!(hS-hR)

While flow transducers installed on water return pipe, the formulation is as below:

Instantaneous Heater rate qh=qV!pR!(hS-hR)

Here:

qV: instantaneous volume flow rate

pS: density in water supply temperature

pR: density in water return temperature

hS: specific heat value in water supply temperature

hR: specific heat value in water return temperature

2) With fixed specific heat value method

qh=qV!C!(tS-tR)

Here:

C: Specific heat value of water, the value can be input in M86

tS: temperature of water supply

tR: temperature of water return

Heat totalizer: Q=Qn+qH!

#t=0.5second, which means totalizer time is 0.5s.

In window menu M8., users can select installing point: water supply direction or water return

direction.

The factory default is water supply installing and GB, standard CJ128 specific heat value.

5.2 Wring Connection of PT100 Resistors

TX1 terminal of flow meter is connected to power supply terminal of PT100 RTD in water supply

pipe.

T1 terminal of flow meter is connected to signal terminal of PT100 RTD in water supply pipe.

TX2terminal of flow meter is connected to power supply terminal of PT100 RTD in water return

pipe.

T2 terminal of flow meter is connected to signal terminal of PT100 RTD in water return pipe.

Two piece of PT100 resistors are common-ground, and connected to terminal GND.