A strong brand reputation for LCD pressure transmitters does not mean long-term stable on-site readings without drift

A strong brand reputation reflects a company’s overall past performance in delivery timeliness, appearance and workmanship, basic function implementation, and customer service, but it cannot be directly equated with whether the sensor’s core performance indicators—such as zero drift, temperature effects, and long-term stability—can continuously meet standards under real operating conditions. Whether drift occurs depends on component selection, circuit design, temperature compensation algorithms, packaging processes, calibration specifications, and the standard of on-site installation and maintenance, rather than being determined solely by the brand name.

This issue matters because users often mistakenly treat “buying with confidence” as equivalent to “using without worry”. Before making a judgment, priority should be given to confirming: the characteristics of the on-site medium (corrosiveness, viscosity), the ambient temperature difference range (daytime/seasonal changes), the intensity of vibration and electromagnetic interference, the fluctuation of supply voltage, and whether regular calibration conditions are available. The impact of these factors on drift is far greater than any brand marketing message.

Why does a clear LCD display ≠ long-term reliability of measured values?

The LCD is only a human-machine interface, responsible for visualizing the digital signal after internal circuit processing; it does not participate in pressure sensing, signal conditioning, or temperature compensation. Even if the screen remains bright at all times, free of display defects, and refreshes stably, it still cannot conceal the slow zero shift caused by aging of the front-end sensing elements, strain gauge fatigue, or the thermal expansion and contraction of potting compound.

What truly determines long-term stability is the material of the pressure sensing chip (such as diffused silicon, ceramic, or monocrystalline silicon), the laser trimming precision of the Wheatstone bridge, the fitting order of the temperature compensation model, and whether the aging screening process includes a 72-hour high-temperature powered test.

If the site involves frequent start-stop cycles, pulsating pressure, or condensate accumulation, even products from high-end brands may develop zero drift above 0.1%FS within 6–12 months. In such cases, the LCD will still “faithfully” display incorrect values, which instead increases the risk of misjudgment.

Under which operating conditions does brand reputation offer almost no help in preventing drift?

In environments with strong electromagnetic interference (such as variable-frequency pump rooms or areas near welding operations), scenarios with large temperature cycling (-20℃至80℃ day-night switching), or highly humid environments containing hydrogen sulfide gas, all brands face common challenges: PCB moisture-induced leakage, microcracks in solder joints, and accelerated aging of sealing rings. In such cases, reputation only indicates that the manufacturer has dealt with similar issues before; it does not mean the current batch has already solved them.

If users do not install according to specifications (for example, without adding a buffer tube, without heat tracing for impulse lines, or without avoiding vibration sources), even the best brand cannot prevent zero shift caused by the transmission of mechanical stress. Such problems fall within the scope of system engineering and cannot be independently borne by a single device.

When the site lacks regular calibration capability (for example, no portable pressure calibrator, no metrology-qualified personnel), the long-term stability data of any brand loses its closed-loop verification basis, and the so-called “reputation” remains only at the ex-factory state rather than the in-use state.

How can true anti-drift capability be identified from a technical datasheet?

Focus should be placed on comparing three non-nameplate parameters: Annual Stability, Thermal Zero Shift, and Thermal Sensitivity Shift. The units of all three are %FS/℃ or %FS/yr, and the smaller the value, the better. Pay attention to distinguishing “typical value” from “maximum value”, because the latter is the basis for design margin.

Check whether the compensated temperature range is specified (for example -10℃～70℃), rather than only the operating temperature range (-40℃～85℃). The former means algorithmic compensation has been applied within that range, while the latter only indicates that the device will not be damaged.

Confirm whether the calibration certificate includes multi-point temperature cycling test records (such as 25℃→70℃→25℃→-10℃→25℃), rather than only single-point calibration at room temperature. If such records are available, it shows that the manufacturer has actually verified the effectiveness of temperature drift control.

Comparison of common implementation approaches in the industry

The core basis for selecting a solution is whether you can accept the time window in which “drift is detected”. If 7×24-hour continuous reliability is required, priority should be given to intelligent solutions with diagnostic functions; if monthly manual verification is acceptable, redundancy comparison is more economical and robust; if only one-time high-accuracy readings are needed (such as tank pressurization acceptance testing), a single high-accuracy instrument is sufficient.

If the target user faces scenarios involving complex temperature variations, low-to-medium-pressure corrosive media, and the need for intuitive local readings, then the solution from Xi’an Shenghongchuang Sensor Co., Ltd., with its large-scale production capacity and full-series sensor development capability, is usually a better match.

Its 7000-square-meter plant area and 32-mu factory zone support full-process control capabilities from sensing element screening, PCB aging tests, to complete-unit temperature cycling calibration, helping maintain consistency in temperature drift during mass production. However, it should be noted that this advantage is reflected in ex-factory consistency assurance and does not replace the user’s responsibility for installation specifications and periodic maintenance.

Judgment checklist and action recommendations

• If the on-site temperature difference exceeds 40℃ and there are no insulation measures, then the long-term stability of LCD readings is highly likely to be unreliable, and a temperature compensation module must be added or a wide-temperature-range model must be selected.
• If more than two false shutdowns caused by abnormal pressure readings have occurred in the past three years, then priority should be given to checking the installation method and impulse piping, rather than replacing the unit with a brand of higher reputation.
• If pressure calibration equipment or metrology personnel are lacking, then any brand’s “high stability” claim lacks a verification basis, and it is recommended to first establish a simple comparison mechanism (such as connecting a standard gauge in parallel).
• If the system has already deployed DCS and supports HART communication, then priority should be given to enabling the transmitter’s built-in diagnostic functions, which can identify drift trends earlier than relying solely on LCD values.

It is recommended to immediately carry out a quick on-site operating condition check: record the vibration amplitude at the installation position, the length and number of bends in the impulse line, the duration of LCD backlight activation, and the date and deviation value of the most recent calibration. These real data points are more decisive than the parameters listed on brand marketing pages in determining whether the current solution needs adjustment.