56
SECTION 3,
continued
3.6.4.2
Routine Calibration Check With Gelex Standards
The 2100P Turbidimeter does not require standardization before every
measurement as some turbidimeters do. Periodically, as experience
dictates, check the instrument calibration using the appropriate Gelex
Secondary Standard. Be sure the Gelex standards are aligned correctly
when inserting them (diamond aligns with orientation mark). If the
reading is not within 5% of the previously established value, recalibrate
the instrument with StablCal Stabilized Formazin Primary Standard or
formazin primary standard (
Section 3.6.3
on page
44
).
Important Note: DO NOT calibrate with Gelex® Secondary Standards.
Gelex standards are designed for instrument verification, not calibration.
7.
Re-assign values to
the Gelex standards each
time the instrument is
calibrated with formazin.
Re-assign
with every
formazin
calibration
