the calibration procedure for micro gear flowmeters after cleaning, incorporating key technical specifications and critical warnings

Here is the professional English translation of the calibration procedure for micro gear flowmeters after cleaning, incorporating key technical specifications and critical warnings:

?? ?Post-Cleaning Calibration Procedure?

I. Pre-Calibration Preparation?

Environmental Control?

Maintain a dust-free, vibration-free environment with stable temperature (20–25°C/68–77°F) to prevent electromagnetic interference.

Equipment & Medium Preparation?

Use calibration instruments with accuracy exceeding the flowmeter’s specifications (e.g., master flowmeters or volume tubes).

Select calibration fluid matching the actual fluid’s viscosity (e.g., high-viscosity lubricating oil); avoid gases or particulates.

Functional Pre-Check?

Manually rotate gears to confirm smooth rotation with no jamming or noise.

Pressure-test seals using soap bubbles to detect leaks.

II. Core Calibration Steps?

(1) Zero Calibration?

Close valves to achieve static fluid conditions; stabilize for 5 minutes.

Adjust the zero-regulation valve or sensor position if readings deviate from zero (allowable drift: ≤±10 pulses).

Critical?: Magnetic gear surface ?must face upward? to ensure signal stability.

(2) Flow Range & Linearity Calibration?

Segmented Flow Testing?

Record readings at low (20%), medium (50%), and high (100%) flow rates against reference standards.

Gradually increase flow to avoid hydraulic shock on gears.

Deviation Correction?

For persistent errors >±0.5%:

Measure gear-to-wall clearance with a micrometer (multipoint average).

Loosen mounting screws, realign gears for frictionless rotation, and retighten.

Hysteresis Verification?

Compare forward/reverse flow readings; hysteresis error should be <0.2%.

(3) Accuracy Validation Methods?

Method? ?Key Steps?

Volumetric Method? Collect fixed fluid volume; compare with flowmeter’s totalized value

Master Meter Method? Connect a reference flowmeter in series; synchronize readings

Acceptance Criteria?: Error ≤±0.5% at all test points with repeatable results.

?? ?III. Post-Cleaning Critical Checks?

Residual Solvent Removal?

Eliminate cleaning agents (e.g., isopropanol) completely to prevent viscosity changes.

Gear Reassembly Validation?

Rotate gears manually 3–5 times to verify proper meshing.

Reinstall gears if magnetic surfaces are misaligned.

Seal Integrity Retest?

Replace all disassembled seals; tighten cover screws diagonally to prevent distortion.

IV. Post-Calibration Maintenance?

Calibration Cycle?: Annually for general use; every 3–6 months in high-contamination/high-use environments.

Quarterly Verification?: Compare with portable master meters; recalibrate if deviation >0.5%.

Failure Analysis?: Replace gear sets if linearity errors persist (indicates eccentric wear).

Run the flowmeter for 24 hours post-calibration to confirm operational stability.

Key Terminology Translations?:

零點(diǎn)校準(zhǔn) → Zero calibration

線性度 → Linearity

回程誤差 → Hysteresis error

滿管無氣穴 → Bubble-free pipe filling

密封圈 → Seals/O-rings