Hach 2100Q User Manual

8.7 Reading modes
1. Push the UP or DOWN key to enter the Reading Options menu.
2. Select Reading Mode to select one of the following options:
Option Description
Normal
(Default
setting)
The normal mode reads and averages three
readings. The result is shown after the reading.
Signal
Average
The Signal Average mode compensates for reading
fluctuations caused by drifting of sample particles
through the light path.
The X-bar icon is shown on the display when signal
averaging is on.
The Signal Average mode measures 12 times and
starts to show the average after three readings. The
final result is the average of all 12 readings.
Rapidly
Settling
Turbidity
(RST)
The Rapidly Settling Turbidity (RST) mode
calculates and continuously updates the turbidity
reading of the sample to a confidence of 95%,
based on the accumulated trend of the real time
measured values.
The RST mode is best used on samples that settle
rapidly and continuously change in value. The
reading is based on a correctly prepared sample
that is homogeneous at the beginning of the
reading. It is best applied to samples that are
greater than 20 NTU. The sample must be mixed
thoroughly by inversion immediately before inserting
it into the meter.
The target icon is shown on the display when the
Rapidly Settling Turbidity is on.
The Rapidly Settling Turbidity reads and calculates
five readings while showing intermediate results.
8.8 Apply silicone oil to a sample cell
Sample cells and caps must be extremely clean and free from significant
scratches. Apply a thin coating of silicone oil on the outside of the
sample cells to mask minor imperfections and scratches that may
contribute to light scattering.
Note: Use only the provided silicone oil. This silicone oil has the same refractive
index as the sample cell glass.
1. Clean the inside
and outside of the
cells and caps by
washing with a
laboratory glass
cleaning detergent.
Follow with multiple
rinses with distilled
or demineralized
water.
2. Apply a small
bead of silicone oil
from the top to the
bottom of the cell.
3. Use the provided
oiling cloth to spread
the oil uniformly.
Wipe off the excess
so that only a thin
coat of oil is left.
Make sure that the
sample cell is almost
dry with little or no
visible oil.
Note: Store the oiling
cloth in a plastic
storage bag to keep the
cloth clean.
English 19

Hach 2100Q Specifications

General

Range	0 - 1000 NTU
Resolution	0.01 NTU on lowest range
Detector	Silicon photodiode
Stray Light	< 0.02 NTU
Measurement Method	Nephelometry
Power Supply	4 AA alkaline batteries
Operating Temperature	0 to 50 °C
Storage Temperature	-20-60°C
Measurement Modes	Signal Averaging, Rapidly Settling Turbidity
Display	LCD
Accuracy	±2% of reading plus stray light from 0 to 1000 NTU
Light Source	Tungsten filament lamp