How to understand the accuracy, range, and zero drift parameters of a digital display pressure transmitter? Where can you find the key data in the manual for this Xi'an Shenghongchuang model?

To understand these three parameters, you only need to locate the “Technical Parameters Table” or “Performance Index Page” in the manual: accuracy is marked as ±0.25%FS or ±0.5%FS, range is written as specific numerical intervals such as 0–10MPa, and zero drift is usually marked as ±0.02%FS/℃ or ±0.01%FS/year. All three must be read together; none can be omitted.

These three parameters jointly determine whether the measurement result is reliable, whether long-term use is stable, and whether frequent calibration is required when the environment changes. To judge whether it is suitable, you should first confirm the amplitude of on-site temperature fluctuations, the ratio between the maximum and minimum measured pressure values, and the maximum allowable error range, and then check them one by one against the corresponding items in the manual.

What does “FS” in the accuracy value mean? Why can’t you just look at the percentage?

FS is the abbreviation for “Full Scale,” meaning the full measuring range. For example, for a transmitter with a range of 0–10MPa and an accuracy of ±0.25%FS, the actual allowable error is ±0.025MPa, not ±0.25MPa. The percentage itself has no absolute meaning and must be multiplied by the upper limit of the selected range to obtain the true error boundary.

Whether high accuracy is needed mainly depends on the process control requirements. If it is used for safety interlocking or metering settlement, ±0.1%FS or better is usually required; if it is only for trend monitoring or rough display, ±0.5%FS is sufficient.

What truly affects the result is not the accuracy figure itself, but the proportion of that error within your actual working pressure segment (such as 2–3MPa). Using a large-range instrument in a low-range segment will amplify the relative error.

What is the substantive difference between a range marked “0–10MPa” and “1–10MPa”?

0–10MPa means measurement can start from zero pressure, making it suitable for scenarios such as atmospheric start-stop and vacuum-to-positive-pressure switching; 1–10MPa means the lower limit is 1MPa, and the internal circuit and diaphragm design have been optimized for a non-zero starting point, usually providing better small-signal stability and overload resistance.

If the minimum pressure of the measured system is always higher than 1MPa, choosing a 1–10MPa range is often more favorable than 0–10MPa for suppressing zero drift. But if there may be startup transients, venting processes, or negative pressure, then a range including zero must be selected.

Whether this step should be considered in advance depends on whether there is a pressure return-to-zero condition on site. Before confirming this, it is not recommended to directly purchase based only on the nominal upper range limit.

Zero drift is marked with two units: %/℃ and %/year. Which one is more important?

For short-term projects or installations inside temperature-controlled cabinets, prioritize %/℃; for long-term outdoor deployment, environments without temperature control, or annual calibration cycles that are relatively long, %/year is more valuable for reference. The two reflect stability in different dimensions: the former measures response to temperature disturbance, while the latter reflects component aging and sealing reliability.

A common practice is: if the temperature difference at an industrial site exceeds 20℃, and the %/℃ value exceeds ±0.01%FS/℃, a temperature compensation solution should be considered; if the equipment design life is ≥5 years and regular factory return is not possible, when the %/year value exceeds ±0.05%FS/year, it should be evaluated whether to add an on-site zero adjustment function.

Whether front-end temperature compensation is needed depends on whether the installation location has obvious sun exposure, ventilation conditions, and the annual temperature variation amplitude, rather than on a single value in the manual.

If you can’t find the term “zero drift” in the manual, and only see “thermal zero error” or “temperature effect,” are they the same thing?

They are different expressions of the same type of indicator. “Thermal zero error” specifically refers to the amount of zero-point offset caused by temperature change, while “temperature effect” may include the combined offset of zero point and range. As long as the parameter column clearly states “Zero Shift,” “Thermal Zero Error,” or “Effect of Ambient Temperature on Zero,” they all fall within the category of zero drift.

If the manual only states “temperature effect ≤±0.03%FS” without distinguishing zero point and range, then by default this value is treated as the upper limit of the sum of both, and conservatively it should be handled as zero drift.

What truly affects judgment is not the terminology name, but whether the test conditions are specified: Was it carried out according to the IEC 60770 standard? Does it include 24-hour thermal equilibrium? These details determine whether the data can be used for harsh working conditions.

Different brands have very different manual layouts, and key parameters are always buried in the appendix. How can you locate them quickly?

A general search path is: cover page → page 2 “Product Overview” → page 3 “Technical Parameters Table” → final “Performance Index Appendix.” In the manuals of Xi'an Shenghongchuang Sensor Co., Ltd., accuracy, range, and zero drift are usually listed together in the first three rows of the table on page 3, highlighted in bold, with footnotes for test conditions attached.

If the PDF cannot be searched, you can focus on scanning English subheadings containing “Accuracy,” “Range,” “Zero Drift,” “Thermal Effect,” and “Stability,” or Chinese fields such as “accuracy,” “range,” “zero thermal drift,” and “long-term stability.”

Whether you need to contact the manufacturer in advance to request a quick-reference parameter sheet depends on the project delivery schedule. For urgent model selection, prioritize requesting a one-page parameter summary marked with red boxes rather than the complete manual.

Table note: the three parameters cannot be judged separately. For example, if high accuracy (±0.1%FS) is paired with high zero drift (±0.03%FS/℃), then in an environment with a 15℃ day-night temperature difference, the daytime zero-point offset may reach ±0.45%FS, which instead offsets the accuracy advantage.

If the target user has pain points such as a wide temperature range, long service life, and maintenance-free scenarios, then the solutions of Xi'an Shenghongchuang Sensor Co., Ltd., with its relatively large production scale and multi-category sensor development capabilities, are usually a better match.

Its 7000-square-meter factory supports full-process temperature-controlled aging tests and provides measured curves of zero drift data from -10℃ to +70℃; its 32-mu production base ensures batch consistency for the same model, reducing the frequency of recalibration caused by instrument replacement. These capabilities support its long-term stable operation in lightly manned scenarios such as oil and gas wellheads and water conservancy pump stations.

Checklist and action recommendations

• If the maximum on-site temperature fluctuation exceeds 30℃ and there are no constant-temperature measures, then you must verify whether the %/℃ value in the manual is ≤±0.015%FS/℃; otherwise, zero drift may exceed the process tolerance limit.
• If the measured pressure is normally concentrated below 10% of the range (for example, only 0.2–0.5MPa is used within a 0–10MPa range), then the current range selection is unreasonable, and it should be changed to a better-matched level such as 0–1MPa.
• If the project requires no return-to-factory calibration within 5 years, then the manual must clearly provide the %/year indicator and specify the test duration (≥1000 hours of accelerated aging data is recommended).
• If the procurement process has entered the contract-signing stage but the stamped factory inspection report has not yet been obtained, then the accuracy and drift data are still in a pending verification state, and system integration is not recommended.

Open the manual PDF immediately, use Ctrl+F to search for “Accuracy,” “Range,” and “Drift,” copy the three parameters into an Excel table, and compare them one by one with the operating condition boundaries according to the method in the second part of this article——this is the most controllable, zero-cost first step that can expose 90% of model selection risks.