1.2 Specifications
1.2.1. Specifications are listed in Table 1.
Table 1
Parameter Value
1. Nominal diameter of the pipeline, DN,
mm 50 80 100 150
2. Minimal measured average volumetric
flow rate Qmin, m3/h 0,28 0,72 1,13 2,5
3. Measured transient average volumetric
flow rate Qtrans, m3/h 1,40 3,62 5,66 12,74
4. Maximal measured average volumetric
flow rate Qmax, m3/h 35 90 150 320
5. Sensitivity threshold, m3/h 0,056 0,144 0,226 0,500
6. Maximal pressure in the pipeline, MPa 1,6
7. Temperature of medium, °C 0-100
8. Power supply voltage, V
- Internal power source
- External power source
3.6 V, when powered from a lithium battery
DC 9...24.5 V
9. Mean time to failure, h 75000
10. Mean life time, years 12
NOTE. Power consumption is no more than 0.9 mW. When charg-
ing the battery after regaining power supply, power consumption is no
more than 1.0 W.
1.2.2. Under normal operating conditions*, the lithium battery keeps the flow-
meter operational for at least 4 years without changing the battery.
* Normal operating conditions are as follows:
- Ambient temperature from +15 to 35 °C
- For frequency / pulse / logical outputs, maximal operating frequency of
no more than 8 Hz
- Logs are read (via RS-485) not more frequently than once a month
- LCD works no more than 3 min per day.
1.2.3. The flowmeter measures average volumetric flow rate at flow velocity
ranging from 0.04 to 5.0 m/s. The relation between flow velocity v and
flow rate in the pipeline Q is determined by the following formula:
2-3DN
10×2,83
Q
=v , (1)
Where Q – average volumetric flow rate, m3/h;
v – flow velocity, m/s;
DN – nominal diameter of the pipeline, mm.
1.2.4. Limits of permissible relative error for measurement, indication, logging,
storage and transferring of average volumetric flow rate and volume
measurement results for any flow direction do not fall outside the follow-
ing ranges:
- From Qmin to Qtrans : no more than ±4 %;
- From Q trans to Qmax: no more than ±2%.
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