Pressure Gauge Form 2: Diaphragm Indication Ledger

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This page now separates a connected qualitative diaphragm-gauge topology from a declared linear dial mapping and a full-span accuracy-class calculation. It does not predict diaphragm deflection, perform calibration or establish instrument suitability or safety.

Declared Diaphragm-Gauge Indication Explorer

Enter declared pressure, zero-to-full-scale range, accuracy class and pointer sweep. The connected view shows the process chamber, clamped diaphragm, centre link, sector, pinion and pointer while the worksheet reports only declared dial mapping and span-based class arithmetic.

0°

Pointer angle
--
Class limit
--
Lower indicated bound
--
Upper indicated bound
--

Equation Used

f=clamp(P/FS,0,1); I=fFS; theta=fS; e=FS*C/100; interval=[max(0,I-e),min(FS,I+e)]
The class limit is simple percent-of-span arithmetic for the declared class and assumes that convention applies. It is not a calibration result or complete measurement uncertainty.
  • The declared scale runs from zero to full scale FS.
  • Pointer mapping is declared linear over sweep S and clamped to the visible scale.
  • Accuracy class C is treated as a uniform percent-of-span limit only for this ledger.
  • The indicated interval is clipped to the declared zero-to-full-scale range.
  • The animation is a prescribed qualitative diaphragm-centre and movement chain; it does not solve diaphragm elasticity or calibrate the linkage.
  • Diaphragm geometry and material, hysteresis, friction, backlash, temperature, pulsation, vibration, overpressure, media compatibility, fatigue, installation, calibration state, uncertainty, selection, maintenance and safety are excluded.

Removes unsupported universal diaphragm travel, movement ratio, stop and service claims while retaining declared linear dial mapping and manufacturer-supported percent-of-span class arithmetic.

A diaphragm element drives a pointer movement

Manufacturer documentation identifies a circular corrugated diaphragm as the measuring element in documented low-pressure gauges, with a mechanical movement and pointer display.

The animation keeps a process chamber, clamped diaphragm centre, link, sector, pinion and pointer visibly connected but prescribes their display motion; it does not solve the diaphragm or calibrate the movement.

Use this page only to audit declared indication arithmetic

The worksheet checks a declared zero-to-full-scale linear pointer mapping and converts a declared uniform percent-of-span class into an absolute pressure limit.

It cannot select, calibrate, certify or diagnose a pressure gauge, and it cannot determine whether an instrument is suitable or safe for a process.

Keep dial mapping separate from diaphragm mechanics

f=clamp(P/FS,0,1); I=fFS; theta=fS
e=FS C/100; interval=[max(0,I-e),min(FS,I+e)]

The class convention must come from the instrument specification. Real diaphragm response and indication error depend on the actual instrument and reference conditions.

A transparent declared-scale example

For P=5.00 bar on a 0–10.00 bar declared scale with a 270-degree sweep, the pointer mapping is 135.0 degrees. A declared class 1.60 percent of span gives an arithmetic limit of ±0.160 bar and a clipped indicated interval from 4.840 to 5.160 bar.

This is not a diaphragm-deflection prediction, calibration certificate or uncertainty statement.

Accuracy class is not the whole measurement result

Real indication depends on the applicable standard and grade, pressure element, range, scale region, reference temperature, hysteresis, friction, backlash, repeatability, vibration, pulsation, mounting, media, overpressure history, condition and calibration.

The former universal diaphragm-bow, motion-ratio, 110-percent stop, fatigue-life, installation-torque, material and application-performance claims are removed because they were not established for one documented instrument.

Diaphragm-gauge ledger questions

Does this predict diaphragm centre deflection?

No. The topology animation is qualitative and prescribed.

Is the pointer always perfectly linear?

No. Linearity here is a declared mapping, not a physical model.

Is the class limit a calibration result?

No.

Can this select a safety-critical gauge?

No.

Diaphragm-gauge references

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