LaMotte 2020wi User Manual

2020

we/wi

1970-EPA
1970-ISO

CONTENTS

GENERAL INFORMATION

 Packaging and Delivery 5
 General Precautions 5
 Safety Precautions 5
 Limits of Liability 6
 Specifi cations 6
 Statistical & Technical Defi nitions 7
 Contents and Accessories 9
 EPA Compliance 10
 ISO Compliance 10
 CE Compliance 10
 IP67 Compliance 10
 Warranty 10
 Register Your Meter 10

COMPUTER CONNECTION 11
BATTERY/AC OPERATION 11
TURBIDITY

 What is Turbidity? 13
 How is Turbidity Measured? 13
 Turbidity Units 15
 Taking Turbidity Water Samples 16
 Sample Dilution Techniques 17

OPTIONS & SETUP

 Factory Default Settings 17
 Averaging 18
 Turbidity Options 20

Selecting Turbidity Units 20
Selecting a Turbidity Calibration Curve 22

 Setting Clock 24
 Setting Power Save 26
 Setting Backlight Time 28
 Factory Reset 30
 Selecting Language 32

DATA LOGGING 34
CALIBRATION & ANALYSIS

 Calibration 36

Turbidity Standards 36
Turbidity Calibration Procedure 37

 Analysis without Blanking Procedure 41
 Analysis with Blanking Procedure 43

 Dilution Procedure 46
 Preparation of Turbidity-Free Water 47
 Testing Tips 48

TROUBLESHOOTING GUIDE

 Troubleshooting 50
 Stray Light 50

GENERAL OPERATING INFORMATION

 Overview 51
 The Keypad 52
 The Display and Menus 52
 Negative Results 54
 Tubes and Chambers 54

MAINTENANCE

 Cleaning 55
 Repairs 55
 Meter Disposal 56

Refer to the Quick Start Guide
for simplifi ed Calibration and
Analysis procedures.

Refer to the Testing Guide for
detailed Calibration and Analysis
procedures for improving the
accuracy of low range turbidity
measurements.

4

GENERAL INFORMATION

 PACKAGING AND DELIVERY

Experienced packaging personnel at LaMotte Company assure
adequate protection against normal hazards encountered in
transportation of shipments.

After the product leaves LaMotte Company, all responsibility for safe
delivery is assured by the transportation company. Damage claims
must be fi led immediately with the transportation company to receive
compensation for damaged goods.

 GENERAL PRECAUTIONS

READ THE INSTRUCTION MANUAL BEFORE ATTEMPTING TO
SET UP OR OPERATE THE METER. Failure to do so could result in

personal injury or damage to the meter. The meter should not be used
or stored in a wet or corrosive environment. Care should be taken to
prevent water from wet tubes from entering the meter chamber.

NEVER PUT WET TUBES IN THE METER.

 SAFETY PRECAUTIONS

Read the label on all reagent containers. Some labels include
precautionary notices and fi rst aid information. Certain reagents are
considered potential health hazards and are designated with a * in the
instruction manual. To view or print a Material Safety Data Sheet (MSDS)
for these reagents go to www.lamotte.com. To obtain a printed copy,
contact LaMotte by e-mail, phone or FAX. Additional information for all
LaMotte reagents is available in the United States, Canada, Puerto Rico,
and the US Virgin Islands from Chem-Tel by calling 1-800-255-3924. For
other areas, call 813-248-0585 collect to contact Chem-Tel’s International
access number. Each reagent can be identifi ed by the four-digit number
listed on the upper left corner of the reagent label, in the contents list
and in the test procedures.

5

 LIMITS OF LIABILITY

Under no circumstances shall LaMotte Company be liable for loss of life,
property, profi ts, or other damages incurred through the use or misuse
of their products.

 SPECIFICATIONS - 2020we/wi

Instrument Type: Nephelometer
Standard: EPA 180.1, 2020we; ISO 7027, 2020wi
Units of Measure: NTU (Nephelometric Turbidity Units) (2020we only)

FNU (Formazin Nephelometric Units) (2020wi only)
ASBC (American Society of Brewing Chemists)
EBC (European Brewery Convention)

Range: 0-4000 NTU, 0-4000 FNU,

0-10,500 ASBC, 0-150 EBC
Range Selection: Automatic
Resolution:

(display)

Accuracy: From 0-2.5 NTU/FNU the accuracy is ±0.05 NTU/

Detection Limit: 0.05 NTU/FNU
Light Source: Tungsten lamp 2300°C ±50 °C, 2020we; IR LED

Detector Photodiode, centered at 90°, maximum peak 400-

Response Time: <2 seconds
Signal

Averaging:
Sample

Chamber:
Sample: 10 mL in capped tube
Display: Graphic Liquid Crystal Display
Software: Auto Shut-off: 5, 10, 30 min, disabled

Languages: English, Spanish, French, Portuguese, Italian,

Temperature: Operation: 0–50 °C; Storage: -40–60 °C

0.01 NTU/FNU, 0–10.99 NTU/FNU Range

0.1 NTU/FNU, 11.0–109.9 NTU/FNU Range

1 NTU/FNU, 110–4000 NTU/FNU Range

FNU. From 2.5-100 NTU/FNU the accuracy is ±2%.

Above 100 NTU/FNU the accuracy is ±3%.

850 nm ±10 nm, spectral bandwidth 50 nm,

2020wi

600 nm, 2020we

Photodiode, centered at 90°, 2020wi

Yes

Accepts 25 mm fl at-bottomed test tubes

Calibration: Field adjustable, blank and 1 point

Data Logging: 500 points

Chinese, Japanese (Kana)

6

Operation

0–90 % RH, non-condensing
Humidity Range:

Auto Shut-off: 5, 10, 30 min, disabled
Waterproof: IP67 with USB port plug in place.

†

Power Source

: USB wall adapter, USB computer connection or

Lithium ion rechargeable battery 2200 mAH, 3.7V
Battery: Charge Life: Approximately 380 tests with backlight

on to 1000 tests with backlight off. (Signal

averaging disabled).

Battery Life: Approximately 500 charges.
Electrical

Provided on nameplate label
Ratings:

Dimensions: (W x L x H) 8.84 x 19.05 x 6.35 cm; 3.5 x 7.5 x 2.2

inches
Weight: 362 g, 13 oz (meter only)
USB Interface mini B

†

CE Mark: The device complies to the product specifi cations for the Low

Voltage Directive.

 STATISTICAL & TECHNICAL DEFINITIONS RELATED

TO PRODUCT SPECIFICATIONS

Method Detection Limit (MDL): “The method detection limit (MDL)
is defi ned as the minimum concentration of a substance that can
be measured and reported with 99% confi dence that the analyte
concentration is greater than zero and is determined from analysis of
a sample in a given matrix containing the analyte.”

1

Note that, “As Dr.
William Horwitz once stated, ‘In almost all cases when dealing with
a limit of detection or limit of determination, the primary purpose of
determining that limit is to stay away from it.’”

2

Accuracy: Accuracy is the nearness of a measurement to the accepted
or true value.3 The accuracy can be expressed as a range, about the
true value, in which a measurement occurs (i.e. ±0.5 ppm). It can also
be expressed as the % recovery of a known amount of analyte in a
determination of the analyte (i.e. 103.5 %).

Resolution: Resolution is the smallest discernible difference between
any two measurements that can be made.

4

For meters this is usually
how many decimal places are displayed. (i.e. 0.01). Note that the
resolution many change with concentration or range. In some cases
the resolution may be less than the smallest interval, if it is possible to
make a reading that falls between calibration marks. A word of caution,
that resolution has very little relationship to accuracy or precision. The
resolution will always be less than the accuracy or precision but it is
not a statistical measure of how well a method of analysis works. The
resolution can be very, very good and the accuracy and precision can

7

be very bad! This is not a useful measure of the performance of a test
method.

Repeatability: Repeatability is the within-run precision.5 A run is a
single data set, from set up to clean up. Generally, one run occurs
on one day. However, for meter calibrations, a single calibration is
considered a single run or data set, even though it may take 2 or 3 days.

Reproducibility: Reproducibility is the between-run precision.

6

Detection Limit (DL): The detection limit (DL) for the 2020we/wi
is defi ned as the minimum value or concentration that can be
determined by the meter, which is greater than zero, independent of
matrix, glassware, and other sample handling sources of error. It is the
detection limit for the optical system of the meter.

1

CFR 40, part 136, appendix B

2

Statistics in Analytical Chemistry: Part 7 – A Review, D. Coleman and L

Vanatta, American Laboratory, Sept 2003, P. 31.

3

Skoog, D.A., West, D. M., Fundamental of Analytical Chemistry, 2nd ed.,

Holt Rinehart and Winston, Inc, 1969, p. 26.

4

Statistics in Analytical Chemistry: Part 7 – A Review, D. Coleman and L

Vanatta, American Laboratory, Sept 2003, P. 34.

5

Jeffery G. H., Basset J., Mendham J., Denney R. C., Vogel’s Textbook of

Quantitative Chemical Analysis, 5

th

ed., Longman Scientifi c & Technical,

1989, p. 130.

6

Jeffery G. H., Basset J., Mendham J., Denney R. C., Vogel’s Textbook of
Quantitative Chemical Analysis, 5th ed., Longman Scientifi c & Technical,
1989, p. 130

88

 CONTENTS & ACCESSORIES

2020we Kit
EPA Version
Code 1970-EPA

Contents Code Code

0 NTU Standard, 60 mL 1480 1480
1 NTU/FNU Standard, 60 mL 1450 1453
10 NTU/FNU Standard, 60 mL 1451 1454
Water Sample Bottle, 60 mL 0688 0688
Tubes, 6 — —
Cable, USB, 3 ft. 1720 1720
USB Wall Adapter 1721 1721

Accessories

Code Description

1452 100 NTU Standard, 60 mL (EPA)
1455 100 FNU Standard, 60 mL (ISO)
0290-6 Tubes, Code 0290, Set of 6
3-0038 Replacement Chamber
4185 Turbidity-Free Water Kit
2-2097 Filters, 0.1 micron, Pack of 50
1901-CD SMARTLink 3 Software
5-0132 Car Charger

2020wi Kit
ISO Version
Code 1970-ISO

99

 EPA COMPLIANCE

The 2020we meter meets or exceeds EPA design specifi cations for
NPDWR and NPDES turbidity monitoring programs as specifi ed by the
USEPA method 180.1.

 ISO Compliance

This 2020wi meter meets or exceeds ISO design criteria for quantitative
methods of turbidity using optical turbidimeters as specifi ed by ISO

7027.

 CE COMPLIANCE

The 2020we and 2020wi meters have been independently tested and
have earned the European CE Mark of compliance for electromagnetic
compatibility and safety. To view certifi cates of compliance, go to the
LaMotte website at www.lamotte.com.

NOTE: The device complies to the product specifi cations for the Low
Voltage Directive.

 IP67 COMPLIANCE

The 2020we/wi meets IP67 standards for protection against dust and
immersion only when the USB port plug is in place. Documentation is
available at www.lamotte.com.

 WARRANTY

LaMotte Company warrants this instrument to be free of defects in
parts and workmanship for 2 years from the date of shipment. If it
should become necessary to return the instrument for service during or
beyond the warranty period, contact our Technical Service Department
at 1-800-344-3100 for a return authorization number or visit
www.lamotte.com for troubleshooting help. The sender is responsible
for shipping charges, freight, insurance and proper packaging to
prevent damage in transit. This warranty does not apply to defects
resulting from action of the user such as misuse, improper wiring,
operation outside of specifi cation, improper maintenance or repair, or
unauthorized modifi cation. LaMotte Company specifi cally disclaims any
implied warranties or merchantability or fi tness for a specifi c purpose
and will not be liable for any direct, indirect, incidental or consequential
damages. LaMotte Company’s total liability is limited to repair or
replacement of the product. The warranty set forth above is inclusive
and no other warranty, whether written or oral, is expressed or implied.

 REGISTER YOUR METER

To register your meter with the LaMotte Service Department, go to
www.lamotte.com and choose SUPPORT on the top navigation bar.

10

COMPUTER CONNECTION

 PC LINK

The 2020we/wi may be interfaced with any Windows-based computer by
using the LaMotte SMARTLink 3 Program and USB Cable. The program
will store test information and results in a database. To transfer data from
the meter to a computer, plug the smaller end of the USB cable (USB
mini B connector) into the meter and the larger end of the USB cable
(USB Type A connector) into a USB port on a computer. The 2020we/
wi will send the following data: test name, wavelength, concentration,
transmittance, absorbance, sample, blank, time of test, and date of test.

 OUTPUT

USB

 COMPUTER CONNECTION

USB Type A, USB mini B, Order Cable Code 1720.

BATTERY/AC OPERATION

The 2020we/wi may be operated on battery power or using USB wall
adapter or USB computer connection. If using the meter as a bench top
unit, use the wall adapter if possible to extend the battery life. The meter
will remain on when the USB adapter is used.

To charge the battery with the wall adapter, plug the smaller end of the
USB cable (USB mini B connector) into the meter and the larger end of
the USB cable (USB Type A connector) into the wall adapter. Plug the
wall adapter into an AC outlet. Reinsert the USB port plug after charging.

To charge the battery from a computer, plug the smaller end of the USB
cable (USB mini B connector) into the meter and the larger end of the
USB cable (USB Type A connector) into a USB port on a computer.
Reinsert the USB port plug after charging.

The battery icon will show no bars and fl ash when the unit fi rst turns on.
Then the indicator will indicate the battery status by showing 0, 1, 2, 3 or
4 bars.

It will take 5 hours to fully charge a low battery. The battery icon will
fl ash when the battery is charging. The battery icon will show four bars
and stop fl ashing when it is fully charged. The charging circuit will
automatically switch to a fl oat charge when the battery is fully charged.
The charger may remain connected. Some computers will NOT supply
power to their USB ports during standby operation. The wall adapter will
charge the unit continuously.

The battery icon will show no bars and continuously fl ash if the battery
is getting low but the unit will still operate normally. A “Low Battery”
message on the status bar of the display will replace the time when the
battery voltage is too low for proper operation and accuracy may be
degraded. A “Shutdown Low Batt” message on the display will appear
for a few seconds before the power is switched off when the battery is
too low to operate the unit.

11

To extend the battery life:

• Shut down the unit with the power switch when not taking
measurements or use the power save option to have the unit
automatically turn off after 5 minutes.

• Store the unit in a cool dry place.

• Fully charge the battery before storing the unit for extended
periods of time.

• Limit backlight use. The unit consumes 3X normal power with
the backlight on. Set the backlight time option to 10 seconds, or
select “Button Control” and keep the backlight off.

Battery replacement: The lithium-ion battery used in this unit should
last for many years with normal use. When it no longer powers the unit
long enough to meet testing requirements it will need to be replaced.
Lithium-ion batteries that are properly charged and stored do not usually
lose all capacity; they just have less capacity after hundreds of charge
cycles. This unit uses a custom battery assembly that is only available
from LaMotte Company. Battery replacement must be performed at a
LaMotte authorized repair facility. The water resistant housing of this
meter should not be opened by the user. Contact LaMotte Company
by phone [phone]) or email ([e-mail]) for a return
authorization number.

12

TURBIDITY

 WHAT IS TURBIDITY?

Turbidity is an aggregate property of the solution, which is water in most
cases. Turbidity is not specifi c to the types of particles in the water.
The particles could be suspended or colloidal matter, and they can
be inorganic, organic or biological. At high concentrations, turbidity
is perceived as cloudiness, haze or an absence of clarity in the water.
Turbidity is an optical property that results when light passing through
a liquid sample is scattered. The scattering of light results in a change
in the direction of the light passing through the liquid. This is most
often caused when the light strikes particles in solution and is scattered
backward, sideways and forward. If the turbidity is low, much of the light
will continue in the original direction. Light scattered by the particles
allows the particle to be ”seen” or detected in solution just as sunlight
allows dust particles in the air to be seen.

In the past 10 years, turbidity has become more than just a measure
of water clarity. Because of the emergence of pathogens such as
Cryptosporidium and Giardia, turbidity now holds the key to assuring
proper water fi ltration. In 1998, the EPA published the IESWTR (interim
enhanced surface water treatment rule) mandating turbidities in
combined fi lter effl uent to read at or below 0.3 NTU. By doing so, the
EPA hoped to achieve a 2 log (99%) removal of Cryptosporidium. There
is presently consideration to lower this to 0.1 NTU. The trend has been
to check the calibration of on-line turbidimeters with hand-held fi eld
units. The optical design and low detection limit of the 2020we/wi allows
very accurate readings for such calibrations.

The meter also allows the user to choose the units of measure for
expressing turbidity. While nephelometric turbidity unit (NTU) has
been the standard for years, FNU (formazin nephelometric unit) and
FAU (formazin attenuation unit) are now being used in ISO 7027 units.
American Society of Brewing Chemists (ASBC) units and European
Brewery Convention (EBC) units allow the brewing industry to check
process waters.

 HOW IS TURBIDITY MEASURED?

Turbidity is measured by detecting and quantifying the scattering of light
in water (solution). Turbidity can be measured in many ways. There are
visual methods and instrumental methods. Visual methods are more
suitable for samples with high turbidity. Instrumental methods can be
used on samples with both high and low levels of turbidity.

Two visual methods are the Secchi Disk method and the Jackson
Candle method. The Secchi Disk method is often used in natural waters.
A black and white Secchi Disk is lowered into the water until it can no
longer be seen. It is then raised until it can be seen again. The average
of these two distances is known as the “Secchi Depth”. The Jackson
Candle method uses a long glass tube over a standard candle. Water
is added or removed from the tube until the candle fl ame becomes
indistinct. The depth of the water measured with a calibrated scale is

13

reported as Jackson Turbidity Units (JTU). The lowest turbidity that
can be determined with this method is about 25 NTU. There are two
common methods for instruments to measure turbidity. Instruments
can measure the attenuation of a light beam passing through a
sample and they can measure the scattered light from a light beam
passing through a sample. In the attenuation method, the intensity
of a light beam passing through a turbid sample is compared with
the intensity passing through a turbidity-free sample at 180° from the
light source. This method is good for highly turbid samples. The most
common instrument for measuring scattered light in a water sample is
a nephelometer. A nephelometer measures light scattered at 90° to the
light beam. Light scattered at other angles may also be measured, but
the 90° angle defi nes a nephelometric measurement. The light source
for nephelometric measurements can be one of two types to meet EPA
or ISO specifi cations. The EPA specifi es a tungsten lamp with a color
temperature of 2,200–3,000 K. The units of measurement for the EPA
method are nephelometric turbidity units (NTU). The ISO specifi es a light
emitting diode (LED) with a wavelength of 860 ± 30 nm and a spectral
bandwidth less than or equal to 60 nm. The units of measurement for
the ISO method are formazin nephelometric units (FNU). The 2020we
meets the EPA specifi cation and the 2020wi meets the ISO specifi cation.
The nephelometric method is most useful for low turbidity.

The 2020we/wi is a nephelometer that is capable of measuring turbidity
by both the attenuation method and the nephelometric method. It uses
a detector placed at 180° to the light source for high turbidity samples.
It uses a detector placed at 90° to the light source for the nephelometric
method for low turbidity samples. The 2020we/wi has a signal averaging
option to improve the stability of readings on low turbidity samples.

The 2020we/wi has two different turbidity calibrations, formazin and
Japan Standard. The formazin calibration is the EPA and ISO approved
method of calibrating nephelometers. This calibration can be used with
user prepared formazin standards or commercially purchased formazin
standards. LaMotte Company approved AMCO

TM

standards labeled for
use with the 2020we/wi can also be used with the formazin calibration.
Stablcal® standards below 50 NTU should not be used to calibrate the
2020we/wi.

The Japan Standard calibration is a calibration for a Japanese Water
Works standard. It is based on Japanese formulated polystyrene
turbidity standards. This calibration should only be used to meet
Japanese Water Works requirements. The Japanese polystyrene
standards can only be purchased in Japan. Formazin, AMCO and
Stablcal

®

standards cannot be used with this calibration.

14

 TURBIDITY UNITS

Traditionally, turbidimeters designed for use in the United State were
made to the specifi cations of EPA Method 180.1. This method defi ned
the NTU, nephelometric turbidity unit, as a unit to measure turbidity
in the range of 0 – 40 NTU using a nephelometer. According to the
EPA a nephelometer was a turbidimeter that measured turbidity with a
90° detector. Also, if the turbidity was greater than 40 NTU, a dilution
was necessary to bring the sample into the 0 – 40 NTU range. Today,
many turbidimeters have additional detectors which increase the range
of the turbidity measurement, eliminate interferences and generally
improve the performance. Currently, many turbidimeters are capable of
measuring above 40 NTU by using detectors other than a 90° detector.
Even though they may use a 180° detector to measure the light that is
attenuated by high turbidity samples they may continue to report the
results as NTU.

Recently there has been an effort to use the units of turbidity
measurements to indicate which type of detector and light source was
used. For EPA compliant meters, measurements made with a 90° degree
detector and an incandescent white light source are reported as NTU.
When an attenuation measurement is made with a 180°detector, using
the same meter, the results are reported as AU, attenuation units. ISO
Method 7027, which specifi es a 860 nm light source, also uses two
turbidity units. When the 90° degree detector is used, the results are
reported as FNU, formazin nephelometric units. With an attenuation
measurement made with a 180°detector, the results are reported as
FAU, formazin attenuation units. It should be noted that all units are
numerically equivalent if the meters are calibrated to formazin and
that the units only designate which detector was used to make the
measurement. For example, 1 NTU = 1 AU = 1FNU = 1FAU.

15

Acronyms Defi nitions Notes

NTU Nephelometric

Turbidity Units

FNU Formazin

Options/Set Up

Nephelometric
Units

AU Attenuation

Units

FAU Formazin

Attenuation
Units

ASBC American

Society of
Brewing
Chemists

EBC European

Brewery
Convention

Regulatory
Method

Incandescent white

EPA 180.1
light between 400 and
600 nm, 90° detection,
2020we

IR LED (usually) 860

ISO 7027
nm, bandwidth less than
60 nm, 90° detection,
2020wi

Incandescent white
light between 400 and

Not

applicable
600 nm, 180° detection,
2020we

IR LED (usually) 860

ISO 7027
nm, bandwidth less than
60 nm, 180° detection,
2020wi

2020we/wi Not

applicable

2020we/wi Not

applicable

The 2020we and 2020wi each use two turbidity units. The 2020we
reports the result as NTU when the 90° detector is used and AU when
the 180° detector is used. The 2020wi reports the result as FNU when
the 90° detector is used and FAU when the 180° detector is used.

 TAKING TURBIDITY WATER SAMPLES

Clean plastic or glass containers may be used for turbidity samples.
Ideally, samples should be tested soon after collection and at the same
temperature as when collected.

16

 SAMPLE DILUTION TECHNIQUES

If a test result is out of the range of the meter, it must be diluted. The
test should then be repeated on the diluted sample. The following table
gives quick reference guidelines for dilutions of various proportions.

Options/Set Up

Amount of Sample Deionized Water to Bring

Final Volume to 10 mL
10 mL 0 mL 1
5 mL 5 mL 2

2.5 mL 7.5 mL 4
1 mL 9 mL 10

0.5 mL 9.5 mL 20

All dilutions are based on a fi nal volume of 10 mL, so several dilutions
will require small volumes of the water sample. Graduated pipets should
be used for all dilutions. If volumetric glassware is not available, dilutions
can be made with the colorimeter tube. Fill the tube to the 10 mL line
with the sample and then transfer it to another container. Add 10 mL
volumes of deionized water to the container and mix. Transfer 10 mL of
the diluted sample to the colorimeter tube and follow the test procedure.
Repeat the dilution and testing procedures until the result falls within
the range of the calibration. Multiply the test result by the dilution factor.
For example, if 10 mL of the sample water is diluted with three 10 mL
volumes of deionized water, the dilution factor is four. The test result of
the diluted sample should be multiplied by four.

Multiplication Factor

OPTIONS & SET UP

 FACTORY DEFAULT SETTINGS

Settings that have user options have been set at the factory to default
settings.

The factory default settings are:

Averaging Disabled
Turbidity Units NTU
Turbidity Calibration Formazin
Date Format MM-DD-YYYY
Power Save 5 minutes
Backlight 10 seconds
Language English

17

 AVERAGING

The averaging option allows the user to average multiple readings. This
option will improve the accuracy of samples with readings that may
tend to drift with time. When the two, fi ve or ten measurement option
has been selected the fi nal average is displayed. The default setting is
disabled. To change the setting:

1. Press and briefl y hold

Options/Set Up

to turn the meter on. The
LaMotte logo screen will
appear for about 3 seconds
and the Main Menu will
appear.

2. Press to scroll to

Options.

3. Press

ENTER

to select

Options.

Main Menu

Measure

Data Logging
Options
Run PC Link

12:00:00 001/500

Main Menu
Measure
Data Logging

Options

Run PC Link

12:00:00 001/500

Options Menu

Averaging

Turbidity Options
Set Clock
Set PWR Save

12:00:00 001/500

4. Press
Averaging.

ENTER

to select

Averaging Menu

Disabled

2 Measurements
5 Measurements
10 Measurements

12:00:00 001/500

18