Pressure Transmitter

A pressure transmitter may leave the factory fully calibrated, thoroughly tested, and perfectly within specification. Yet once installed on site, it suddenly starts giving unstable readings, drifting values, or inaccurate measurements. Why? In many cases, the problem is not the instrument itself — it’s how the transmitter is selected, installed, and applied in real operating […]

The nameplate of a differential pressure (DP) transmitter may state an accuracy of ±0.075%, ±0.05%, or even ±0.04%. Many users assume this is the actual measurement accuracy they will achieve in the field. In reality, the final measurement error can be significantly higher due to factors such as turndown ratio, temperature changes, static pressure effects,

Pressure transmitters are among the most commonly used instruments in industrial settings. Despite their frequent usage, a simple yet often overlooked operation—zero calibration—is essential for maintaining accurate measurements. Why Do Pressure Transmitters Need Zero Calibration? Zero point shifts in pressure transmitters are common, typically caused by one or more of the following six factors: Changes

The Hidden Reason Experienced Engineers Always Know If you have ever walked through an industrial plant, you may have noticed that many pressure gauges are not connected directly to the pipeline. Instead, there is often a curved metal tube installed between the gauge and the process connection — usually in a U-shape, pigtail, or loop

Absolute pressure measurement refers to the pressure of a medium relative to absolute vacuum (0 pressure reference), which is different from gauge pressure that is referenced to atmospheric pressure. Absolute pressure transmitters are widely used in vacuum systems, sealed tanks, gas pipelines, distillation towers, and process pressure monitoring applications where accurate pressure measurement relative to

In any industrial automation system, inaccurate pressure measurement can compromise safety, product quality, and process stability. A pressure transmitter is often referred to as the “nerve ending” of a control system. If its zero point drifts, every downstream control action — from PID regulation to safety interlocks — may operate on incorrect data. Zero calibration

In field maintenance, engineers often encounter this situation: The zero point cannot be adjusted back to 4 mA The full-scale output cannot reach 20 mA Mid-range readings show serious deviation Many technicians keep trying to adjust zero and span repeatedly. However, once the deviation exceeds the transmitter’s internal adjustment range, calibration will no longer solve

In industrial sites, pressure-related issues occur almost every day: Unstable pressure readings Fluctuating or drifting signals Frequent instrument damage Complaints about poor accuracy shortly after commissioning After investigation, the conclusion is often the same: The instrument itself is not defective — the problem started with incorrect selection. This issue is especially common when choosing between

1. Nitrogen-Hydrogen Compressor Stage 3 Outlet Pressure Display is Lower Than the Local Pressure Gauge Fault InspectionThe pressure displayed on the control panel is 0.6 MPa lower than the local pressure gauge. We checked and calibrated both the pressure gauge and the pressure transmitter, and both were accurate. However, the two readings still did not

In industrial settings, there’s a dangerous “knee-jerk” reaction that can be costly: Whenever the pressure transmitter readings fluctuate, technicians often suspect the device is faulty and immediately request a replacement. What happens next? A new transmitter is installed, but within a few days, the same “drift” occurs again. Engineer Li, with years of experience in