| |
Pipe ID (mm) |
Accuracy
(%) |
Minimal Flowrate Detectable |
Min. Flowrate
|
Max. Flowrate |
Cumulative Flowrate
|
Cumulative Heat Quantity
|
Max. Reading |
Min. Reading |
Max. Reading |
Min. Reading |
（m3/h） |
32 |
1.0 |
0.0073 |
0.092 |
12 |
99999.999
|
0.001
|
99999.999
|
0.001
|
40 |
0.0114 |
0.144 |
20 |
50 |
0.0353 |
0.35 |
150 |
9999999.9
|
0.1
|
9999999.9
|
0.1
|
65 |
0.06 |
0.60 |
180 |
80 |
0.09 |
0.9 |
230 |
100 |
0.141 |
1.41 |
300 |
125 |
0.221 |
2.21 |
360 |
150 |
0.318 |
3.18 |
460 |
200 |
0.565 |
5.6 |
660 |
250 |
0.883 |
8.83 |
740 |
|
| |
Note: For pipes DN32and DN40, the readings of cumulative heat quantity are all in unit of MJ. |
| |
Pipe-section-mounted Transducer Mounting Conditions & Requirements |
| |
Mounting Position |
| |
*The length of the straight pipe section should meet the following requirements (D – Pipe ID) |
| |
The length of the pipe section on upstream side of transducer should be no less than 10D, and that on downstream side of |
| |
transducer should be no less than 5D. If the required conditions are not available on site, a flow-regulating device should be |
| |
provided on upstream side, for reduced eddies in flow, improved distribution of flow velocity field, and greater precision and |
| |
stability of flowmeter. If a reduced flow velocity may lead to reduction of eddies and improvement of flow velocity distribution, |
| |
the length of the upstream straight pipe section can be shortened to less than 10D. However, when there exist on upstream |
| |
side of transducer 90°pipe bends or other flow-resisting elements, the length of the upstream straight pipe section is required |
| |
to be greater than 10D. |
| |
*Recommended mounting position |
| |
（1）The measuring point should be selected on an upright pipe with either upward or inclined upward flow, or possibly on |
| |
a horizontal pipe. Avoid as much as possible, the use of a transducer on a pipe with downward or inclined downward flow, as |
| |
the pipe may not be fully filled with fluid in this case. |
| |
（2）Never mount a transducer at the highest point of a pipe run because abnormalities in measurement may occur in this |
| |
case due to accumulation of air bubbles at this point of the pipe. |
| |
（3）On a horizontal pipe, the mounting position of the transducer should be within±45°from the horizontal line, for avoiding |
| |
the contact of ultrasonic beam with the air bubbles at the top of the pipe. |
| |
Temperature sensor mounting position |
| |
The supply-water temperature sensor (high-temperature point) must be fitted on the downstream side of the flowrate trans- |
| |
ducer at a point about 50mm~100mm away from the downstream flowrate transducer. The return-water temperature sensor |
| |
(low-temperature point) should be mounted in close proximity to the supply water temperature sensor. |
| |
Special Note: It is not allowed to arbitrarily change the length of the cable of either the flowrate transducer or temperature s- |
| |
ensor, and the 2 cables should be equal in length! |
