Sieve shaker · Calibration procedure
Sieve aperture verification
Checks that the mesh openings of each test sieve are within the tolerances for its nominal size, by optical measurement or with certified calibration material.
PURPOSE
Why this is checked
Sieve meshes stretch, dent and wear with use. A sieve with enlarged openings lets coarse particles through and makes the product look finer than it is.
Frequency
Typically annually (more often for heavily used fine sieves), and whenever damage is suspected, as defined in your SOP.
Learn how the Sieve shaker worksYOU WILL NEED
Standards & tools
- Calibrated measuring microscope or optical sieve analyser with a traceable scale
- Or certified calibration spheres / reference material for the sieve size
- Supplier's certificate of compliance with ISO 3310-1 or ASTM E11
BEFORE YOU START
Prerequisites
- Sieve clean and dry
- Visual inspection done: no holes, tears, loose wires or frame damage
PROCEDURE
Step by step
- 1Inspect the mesh against a light for damage; reject damaged sieves straight away.
- 2Measure a set number of apertures in both directions at several locations across the mesh (as per the standard or SOP).
- 3Calculate the mean aperture and note the largest single aperture.
- 4Compare the mean with the nominal size and the tolerances in ISO 3310-1 / ASTM E11.
- 5Record the result against the sieve serial number.
RECORD
Example observation table
| Sieve (nominal) | Apertures measured | Mean (µm) | Largest (µm) | Deviation of mean |
|---|---|---|---|---|
| 250 µm | 248, 255, 251, 253, 250, 256, 249, 252, 254, 251 | 251.9 | 256 | +1.9 µm (+0.76%) |
CALCULATION
How to calculate the result
Mean aperture = Σ measured apertures ÷ n; Deviation = Mean − Nominal
- Sum of 10 apertures = 2519 µm
- Mean = 2519 ÷ 10 = 251.9 µm
- Deviation = 251.9 − 250 = +1.9 µm (+0.76%)
ACCEPTANCE CRITERIA
Pass if
- Mean aperture and largest individual aperture within the ISO 3310-1 / ASTM E11 tolerances for that nominal size (see the standard's table).
- No visible damage, holes or loose wires.
IF IT FAILS
What to do
- Withdraw the sieve from use and label it rejected.
- Replace with a certified sieve.
- Assess results obtained with that sieve since the last verification.
MORE
Other Sieve shaker calibrations
In LimsPulse · Calibration Management
LimsPulse schedules this calibration, records the result against limits, and blocks the instrument everywhere if it fails or goes overdue.