Atlas SQN

The Lab — fibre counting

SQN-APM-MET-002 · NOHSC:3003 (2005) membrane filter method

starting…

Who is counting?

Every count, check and signature is recorded against you — not against the tablet.

not ready

Test slide check

Block 5 visible?
Block 6 partially visible?
Block 7 detected?

Block 5 visible, block 6 at least partly (faint lines are enough), and block 7 not at all. Optics that resolve further than the method allows are as much a failure as optics that resolve less.

Once a day per laboratory, before client samples. Recorded once, it carries every sitting at this site until midnight.

Calibration constants

Choose the site and the microscope.

Samples

Certificate of Analysis

Sample

Low-power scan passed?

Even loading across the filter, and a dust-free circumference where the cowl sat. A rejected filter cannot be counted.

allocated when saved

Before counting starts

    Fibre count

    On field 1 counted 0 of 100
    space zero & next 0–9 count & next 1. one and a half . a half & next +- add or take off a half r reject field ←→ move ↑↓ a row ⌫ back & clear

    One end of a fibre inside the graticule counts as a half. A field with more than an eighth obscured by an agglomerate is rejected and another counted — a rejected field is recorded, not skipped.

    Result

    —

    fibres/mL

    Counted —
    Volume —
    Loading —
    95% CI —