Relationship Between the Design Principle and Measurement Accuracy of Insertion Electromagnetic Flowmeters

As a professional manufacturer of flow control equipment, Xi'an Shenghongchuang conducted a dedicated field test on the insertion design of the RXLDB electromagnetic flowmeter. This article provides an in-depth analysis of the impact of the insertion-type PTFE rubber lining structure on the measurement accuracy of electromagnetic flowmeters in the LY-LDE-C, UHLDB, and other series, offering key performance data references for technical evaluators.

The measurement accuracy of electromagnetic flowmeters is affected by many factors, among which insertion design is one of the key technical parameters. Compared with traditional full-bore flowmeters, insertion electromagnetic flowmeters estimate the total flow rate by measuring the centerline velocity in the pipeline, and their accuracy performance is directly related to the reliability of industrial process control. This field test specifically focused on the effects of lining material (PTFE rubber) and insertion depth on the output stability of flow sensors such as the LY-LDE-WS and HPLDE models.

Field Test Environment and Experimental Design

The test was conducted in an ISO/IEC 17025 certified laboratory, using multiple pipe diameter combinations from DN50-DN300, with fluid media including clean water, low-conductivity solutions（5μS/cm）and liquids containing suspended particles. The tested equipment covered mainstream models such as JCLDBE and RT-LDE, and all flowmeters were calibrated in accordance with the GB/T 18659-2018 standard.

• Test equipment：RXLDB electromagnetic flowmeter prototype（adjustable insertion depth）
• Control group：Traditional full-bore flowmeters of the XFE and XFC series
• Data acquisition：Instantaneous flow rate recorded every10seconds for72hours
• Accuracy evaluation：Referenced JJG 1030-2020 verification regulation for electromagnetic flowmeters

Impact of PTFE Rubber Lining on Signal Stability

Field test data show that the HKE electromagnetic flowmeter using insertion-type PTFE rubber lining performed outstandingly under the following operating conditions：

The PTFE rubber material demonstrated excellent chemical stability and was still able to maintain the insulation performance of the electrodes in strongly corrosive media. Compared with ordinary rubber lining, its dielectric constant variation rate was reduced by63%, effectively suppressing interference from polarization voltage on the measurement signal.

Insertion Depth Optimization Plan

By changing the insertion depth of the UHLDB electromagnetic flowmeter（10%-90% pipe diameter）, we found：

1. Optimal insertion point：At the30%-50% pipe diameter position, the velocity distribution coefficient K value was closest to the theoretical value of0.82
2. Laminar flow conditions：When the insertion depth exceeds70%, boundary layer effects will occur, and accuracy will decrease by0.3-0.5 classes
3. Turbulent flow conditions：At40% insertion depth, accuracy of0.8 class can still be maintained when Reynolds number Re＞10000

It is recommended that when installing the LY-LDE-C electromagnetic flowmeter, our company's patented depth-positioning flange（Patent No. ZL202120XXXXXX）be used to ensure that the probe is always at the optimal measurement position.

Industry Application Recommendations and Selection Guide

According to the field test data, the applicable scenarios for different models of electromagnetic flowmeters are as follows：

Chemical Industry

The RXLDB electromagnetic flowmeter, combined with PTFE rubber lining, is particularly suitable for strong acid and strong alkali media. In the98% concentrated sulfuric acid conveying test, the annual drift was＜0.2%, significantly better than the ordinary316L electrode solution.

Water Treatment Industry

The insertion design of the LY-LDE-WS model reduces installation cost by40% and facilitates maintenance in large-diameter wastewater measurement applications above DN800. Field test data from municipal wastewater treatment plants show that its long-term stability error is＜1.5%.

Technical Summary and Solutions

This dedicated field test verified that：

• After design optimization, insertion electromagnetic flowmeters can achieve0.5 class accuracy, meeting the requirements of most industrial scenarios
• PTFE rubber lining extends the service life of models such as HPLDE by3-5times in corrosive media
• Through a dynamic compensation algorithm, the error of the JCLDBE model under pulsating flow conditions is controlled within1.2%

As a national high-tech enterprise, Xi'an Shenghongchuang has20years of experience in the R&D of flow measurement equipment. Our engineering team can provide you with：

1. Customized insertion depth calculation services
2. On-site installation guidance and calibration
3. 7×24-hour technical support

Contact our technical consultants now：Call029-XXXXXXX or visit www.shengchuang.com to obtain the Electromagnetic Flowmeter Selection White Paper and the complete field test data report.