ELECTROMAGNETIC FLOW METER
DESCRIPTION
The electromagnetic flowmeter is based on the Faraday's law of electromagnetic induction. A pair of detection electrodes are installed on the tube wall perpendicular to the measuring tube axis and the magnetic field magnetic field lines. When the conductive liquid moves along the measuring tube axis, the conductive liquid performs cutting magnetic field lines to generate an induced potential. This induced potential is detected by two electrodes on the measuring tube, and the value is:
The measured flow rate is that the fluid flows through a magnetic field perpendicular to the direction of flow, and the flow of the conductive fluid induces a potential proportional to the average flow rate, so the measured liquid is required to have a conductivity higher than the minimum. The induced voltage signal is detected through two electrodes and transmitted to the converter through a cable. After a series of digital processing, the accumulated flow and homeopathic flow are displayed on the display of the converter.
TECHNICAL STANDARD
All indicators should comply with the latest editions of the relevant national or industry standards:
1.Metrology Law of the People's Republic of China
2.Detailed Rules for the Implementation of the Metrology Law of the People's Republic of China
3.JB / T 9248—2015 《Electromagnetic Flowmeter》
4.GB/T 778 "Drinking cold water meter and hot water meter"
5.JJG 162 "cold water meter"
6.CJ / T224 "Electronic remote water meter"
7.JJG1033-2016 "Assessment Standards for Measurement Standards"
8.JG / T162-2017 "Remote Meter Reading System for Civil Buildings"
9.CJ / T364-2011 "Requirements for Online Calibration of Pipeline Electromagnetic Flowmeters"
10.GB/T 17219 "Safety Evaluation Standards for Drinking Water Transmission and Distribution Equipment and Protective Materials"
11.GB/T 9112-2010 《Types and parameters of steel pipe flanges》
12GB / T 20729-2006 "Flange-mounted electromagnetic flowmeter for measuring conductive liquid flow in closed pipelines"
13) GB 3836 "National Standard for Explosion Protection"
14) GB 4208—2008 "National Standard for Shell Protection Level"
TECHNICAL PARAMETERS
1.Flow parameter
| Nominal caliber (mm) |
Minimum flow (m3 / h) |
Maximum flow (m3 / h) |
Pressure rating (MPa) |
| 50 |
2.1 |
84.8 |
1.0 |
| 65 |
4 |
143 |
1.0 |
| 80 |
5 |
217 |
1.0 |
| 100 |
8 |
339 |
1.0 |
| 125 |
13 |
530 |
1.0 |
| 150 |
19 |
763 |
1.0 |
| 200 |
30 |
1360 |
1.0 |
| 250 |
50 |
2120 |
1.0 |
| 300 |
80 |
3050 |
1.0 |
| 400 |
140 |
5430 |
1.0 |
| 500 |
210 |
8480 |
1.0 |
| 600 |
300 |
12200 |
1.0 |
2.Measurement range velocity: ≤12m / s
3.The accuracy level and the basic error limit of the intelligent variable measurement range flowmeter meet the following requirements:
| level of accuracy |
0.2 |
| Basic error limit (%) |
±0.2 |
a) When the ambient temperature changes within the working ambient temperature range, the lower limit value of the output signal of the converter and the amount of range change do not exceed 1/2 of the absolute value of the basic error limit of the flowmeter for every 10 ° C change in temperature.
b) After the converter has passed the environmental relative humidity impact test at a temperature of 40 ° C ± 2 ° C and a relative humidity of (93 ± 3)% for 48 hours, the output signal lower limit value and range change should exceed the basic error of the flow meter Limit 1/2 of absolute value.
4. Working environment
| Environmental conditions |
Type |
sensor |
converter |
| Ambient temperature |
Split type |
-40℃～+65℃ |
-40℃～+65℃ |
| -40℃～+65℃ |
| Relative humidity |
Split type |
5%～95% |
5%～90% |
The converter should be guaranteed to work normally at -40 ℃ for a long time.
5.Shell protection level
5.1 The protection level of submersible sensors meets IP68 specified in GB 4208—2008.
5.2 Diving time limit: The sensor works continuously in the diving mode, and the electromagnetic flowmeter can maintain normal working status during the warranty period.
6. Compressive strength
The measuring tube of the flowmeter sensor should be able to withstand a compressive strength test with a test pressure of 1.5 times the rated working pressure for 5 minutes without leakage or damage.
7.Connection size
The flange connection size of the flange connection type flowmeter complies with the regulations of GB / T 9112—2010. The length between the flange end faces of DN15 ～ DN600 flange-connected sensors with nominal diameters complies with the regulations of GB / T 20729-2006.
8. Lead seal is reserved for electromagnetic flowmeter.
FUNCTIONAL
1.Pressure function: It has a pressure display function and can detect the water pressure data of the pipeline at the same time. It has a pressure transmitter function.
2.Communication channel:
Interface: RS232, RS485.
Reporting channels: 4G, GPRS, NB-IOT.
Network type: Three Netcom.
The intelligent flowmeter can communicate with the host computer in two directions and is interoperable
3.Power supply: battery-powered:
a)The battery should be replaceable.
b)The battery has been in the working environment at -40 ℃ -65 ℃ for a long time.
4.Reporting function:
4.1 Periodic reporting: Daily periodic reporting: Report the 24-hour data of the previous day.
4.2 The reporting success rate is 100% and the reading accuracy rate is 100%.
4.3 Replenishment function: When the data report is unsuccessful, the data will be replenished automatically in the next reporting period, and the data can be replenished during the effective storage period of the data.
4.4 Data report message: The data report message is sent in a complete message message.
4.5 Setting function: Parameter setting can be performed through the application platform or handheld device.
4.6 Reporting and resending mechanism settings: The data reporting is unsuccessful, the electromagnetic flowmeter data is resent, and the number of resendings can be set.
4.7 Time proofreading: When the data period is reported, it has the time proof function for proofreading.
4.8 The electromagnetic flowmeter data can be automatically uploaded to the server to achieve remote data monitoring.
5.Alarm function: when the water flow exceeds the maximum flow rate of the electromagnetic flowmeter or the battery is under pressure, it will alarm.
6.Display function: The intelligent flowmeter should have the function of displaying flow rate, flow rate, percentage flow rate and other fluid parameters, and can display the cumulative amount of forward flow, the cumulative amount of reverse flow, and the difference between the cumulative amount of forward and reverse flow. A flowmeter with a self-test function should be able to display self-test status, alarm information, and other content.
7.Configuration function: The intelligent flowmeter has the following configuration setting functions, and each function should be able to work normally:
7.1Parameter setting: sensor coefficient setting, small signal cut-off; upper and lower limit alarm ranges;
7.2Frequency output: current signal 4-2mA
The voltage signal is 0-5V.
7.3Engineering unit selection: m 3 / h, m 3 / min, m 3 / s, L / h, L / min, L / s, m 3 and L, etc.
8.Self-diagnostic function: The intelligent flowmeter has a self-diagnostic function that judges and prompts parameter settings and abnormal measurement processes.
9.Air traffic detection: It has the function of air traffic detection, and can prompt the alarm through the remote transmission platform in time.
10.Forward and reverse flow measurement function: The intelligent flow meter can automatically determine and measure the forward and reverse flow and output the corresponding flow signal.
11.Power-off protection function: The intelligent flow meter has a power-off protection function. When the power is interrupted, the setting parameters and accumulated total data should be accurately maintained. After the power is restored, there is no need to reset.
12.Password lock function: The parameter setting function of the intelligent flow meter adopts multi-level encryption protection, and masters the operation password according to the responsibility authority to prevent non-professional operators from misoperation.
13.Appearance and screen display:
The flowmeter has all markings (nameplates, explosion-proof signs, diving signs, manufacturing equipment licenses and signs, etc.) correct, complete, and clear; the joint surface of the external connection should be free of scratches, etc. No coating defects such as peeling and peeling.
The numbers of the display window are conspicuous and neat, and the text symbols and signs indicating the functions should be complete, clear, and correct; the protective glass on the reading device should have good transparency and no reading defects such as reading distortion; the keys are not stuck.
