Principle Of Operation; Preparation For Use; Unpacking - Hach 2100P ISO Manual

SECTION 1,
Formazin Standards; 4 AA alkaline batteries; 15 mL of silicone oil;
oiling cloth; carrying case; instrument manual; and quick reference card.

1.3 Principle of Operation

The Model 2100P ISO Portable Turbidimeter operates on the
nephelometric principle of turbidity measurement. This instrument
meets the design criteria specified by ISO 7027.
The ratio optical system* (Figure 2) includes an LED lamp, a 90°
detector to monitor scattered light, and a transmitted light detector. The
microprocessor calculates the ratio of the signals from the 90° and
transmitted light detector. This ratio technique corrects for interferences
from color and/or light absorbing materials (such as activated carbon)
and compensates for fluctuations in lamp intensity, providing long-term
calibration stability. The optical design also minimizes stray light,
increasing measurement accuracy.
Figure 2 Ratio Optical System
Lamp

1.4 Preparation for Use

1.4.1 Unpacking

Remove the instrument and accessories from the shipping box and
inspect for damage that may have occurred due to rough handling or
* Patent number 4,198,161; other patents pending.
continued
Lens
90°
Detector
Sample
Cell
16
Transmitted
Light
Detector