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:

零点校准 → Zero calibration

线性度 → Linearity

回程误差 → Hysteresis error

满管无气穴 → Bubble-free pipe filling

密封圈 → Seals/O-rings