Page 1
2020
we/wi
1970-EPA
1970-ISO
Page 2
Page 3
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
Page 4
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
Page 5
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
Page 6
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
Page 7
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
Page 8
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
Page 9
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
Page 10
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
Page 11
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
Page 12
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 (1-800-344-3100) or email (tech@lamotte.com) for a return
authorization number.
12
Page 13
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
Page 14
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
Page 15
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
Page 16
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
Page 17
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
Page 18
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
Page 19
5. Press or to scroll
to the desired option.
Averaging Menu
Disabled
2 Measurements
5 Measurements
10 Measurements
12:00:00 001/500
Options/Set Up
6. Press
ENTER
to save the
selection. The screen will
display Storing... for about
1 second and return to the
Options Menu.
Averaging
Turbidity Options
Set Clock
Options Menu
Set PWR Save
12:00:00 001/500
NOTE: When the Averaging option is enabled, more time will be
required to display a reading and more power will be used.
19
Page 20
TURBIDITY OPTIONS
The default units are NTU and FNU and the default calibration curve is
formazin. NTU will be used in this example. To change the settings:
Selecting Turbidity Units
1. Press and briefl y hold
to turn the meter on. The
Options/Set Up
LaMotte logo screen will
appear for about 3 seconds
and the Main Menu will
appear.
Measure
Data Logging
Options
Run PC Link
12:00:00 001/500
Main Menu
2. Press to scroll to
Options.
3. Press
ENTER
to select
Options. Press to scroll
to Turbidity Options.
4. Press
ENTER
to select
Turbidity Options.
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
Turbidity Options
Turbidity Units
Turbidity Calibration
12:00:00 001/500
20
Page 21
5. Press
Turbidity Units.
ENTER
to select
NTU
Set Turbidity Units
ASBC
EBC
12:00:00 001/500
Available units are:
NTU (Nephelometric Turbidity Units)( 2020we only)
FNU (Formazin Nephelometric Units) (2020wi only)
ASBC (American Society of Brewing Chemists)
EBC (European Brewery Convention)
NOTE: The meter will automatically switch to the attenuation mode
above 600 NTU or FNU. In Attenuation mode, measurements will be
made with the 180° detector only, as indicated by AU (attenuation units)
or FAU (formazin anttenuation units) on the display. AU and FAU are
numberically equivalent to NTU. See page 15 for defi nitions of turbidity
units.
Options/Set Up
6. Press or to scroll
to the desired units.
7. Press
ENTER
to save the
selection. The screen will
display Storing... for about
1 second and return to the
Turbidity Options menu.
Press
EXIT
to return to a
previous menu.
Set Turbidity Units
NTU
ASBC
EBC
12:00:00 001/500
Turbidity Options
Turbidity Units
Turbidity Calibration
12:00:00 001/500
21
Page 22
Selecting a Turbidity Calibration Curve
1. Press and briefl y hold
to turn the meter on. The
LaMotte logo screen will
appear for about 3 seconds
and the Main Menu will
appear.
Options/Set Up
Main Menu
Measure
Data Logging
Options
Run PC Link
12:00:00 001/500
2. Press to scroll to
Options.
3. Press
ENTER
to select
Options. Press to scroll
to Turbidity Options.
4. Press
ENTER
to select
Turbidity Options.
Main Menu
Measure
Data Logging
Options
Run PC Link
12:00:00 001/500
Options Menu
Averaging
Turbidity Options
Set Options
Set PWR Save
12:00:00 001/500
Turbidity Options
Turbidity Units
Turbidity Calibration
12:00:00 001/500
5. Press to scroll to
Turbidity Calibration.
Turbidity Options
Turbidity Units
Turbidity Calibration
12:00:00 001/500
22
Page 23
6. Press
ENTER
to select
Turbidity Calibration.
Turbidity Calibration
Formazin
Japan Standard
12:00:00 001/500
Options/Set Up
7. Scroll to the desired
calibration option. Select
a calibration option based
on the composition of the
Formazin
Japan Standard
Turbidity Calibration
standards that will be used to
calibrate the meter.
12:00:00 001/500
NOTE: Stablcal® standards below 50 NTU should not be used to
calibrate the 2020we/wi. The diluent has a different refractive index than
traditional formazin standards and will affect the results.
8. Press
ENTER
to save the
selection. The screen will
display Storing... for about
1 second and return to the
Turbidity Units
Turbidity Calibration
Turbidity Options
Turbidity Options menu.
Press
previous menu.
EXIT
to return to a
12:00:00 001/500
23
Page 24
SETTING THE CLOCK
1. Press and briefl y hold
to turn the meter on. The
LaMotte logo screen will
appear for about 3 seconds
and the Main Menu will
appear.
Options/Set Up
2. Press to scroll to
Options.
3. Press
ENTER
to select
Options. Press
to Set Clock.
to scroll
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
ENTER
to select
Set Clock. The date is
displayed as month-day-year.
The time is displayed as
hours:minutes:seconds
AM/PM. Press
or
to the appropriate character
and press
ENTER
to select. The
cursor will move to the next
character. Set all characters
in the same manner. This is a
scrolling menu.
Set Time
Date: 07-09-2010
Time: 02:09:08 PM
12:00:00 001/500
24
Page 25
5. Press
ENTER
to select the fi nal
character. The time and date
will be saved and the screen
will return to the Options
Menu.
Options Menu
Averaging
Turbidity Options
Set Clock
Set PWR Save
12:00:00 001/500
Options/Set Up
25
Page 26
SETTING POWER SAVE
The power saving Auto Shutoff feature will turn the meter off when a
button has not been pushed for a set amount of time. The default setting
is 5 minutes. To change the setting:
1. Press and briefl y hold
to turn the meter on. The
Options/Set Up
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 to scroll to Set
PWR Save.
Options Menu
Averaging
Turbidity Options
Set Clock
Set PWR Save
12:00:00 001/500
26
Page 27
5. Press
Save.
ENTER
to select PWR
Auto Shutoff
Disable
5 Minutes
15 Minutes
30 Minutes
12:00:00 001/500
Options/Set Up
6. Press or to scroll
to desired setting.
7. Press
ENTER
to save the
selection. The screen will
display Storing... for about
1 second and return to the
Options Menu.
Auto Shutoff
Disable
5 Minutes
15 Minutes
30 Minutes
12:00:00 001/500
Options Menu
Averaging
Turbidity Options
Set Clock
Set PWR Save
12:00:00 001/500
27
Page 28
SETTING THE BACKLIGHT TIME
The backlight illuminates the display for enhanced viewing. If Button
Control is chosen the backlight button on the key pad will act as an
on/off switch and the backlight will remain on or off when the meter is
being used. When one of the other settings – 10, 20 or 30 seconds –
is chosen, the display will be illuminated for the specifi ed amount of
time after any button is pressed. As a precaution, the backlight will not
illuminate during turbidity measurements to avoid interference from stray
Options/Set Up
light.
NOTE: The backlight feature uses a signifi cant amount of power. The
longer the backlight is on, the more frequently the battery will have to be
charged if the USB/Wall Charger is not being used.
1. Press and briefl y hold
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
28
Page 29
4. Press to scroll to Set
Backlight Time.
Options Menu
Turbidity Options
Set Clock
Set PWR Save
Set Backlight Time
12:00:00 001/500
Options/Set Up
5. Press
ENTER
to select Set
Backlight Time.
6. Press or to scroll
to desired setting.
7. Press
ENTER
to save the
selection. The screen will
display Storing... for about
1 second and return to the
Options Menu.
Backlight Time
Button Control
10 Seconds
20 Seconds
30 Seconds
12:00:00 001/500
Backlight Time
Button Control
10 Seconds
20 Seconds
30 Seconds
12:00:00 001/500
Options Menu
Turbidity Options
Set Clock
Set PWR Save
Set Backlight Time
12:00:00 001/500
29
Page 30
FACTORY RESET
Performing a Factory Reset will restore the factory default settings. All
user-level calibrated settings will be lost.
1. Press and briefl y hold
to turn the meter on. The
LaMotte logo screen will
Options/Set Up
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 to scroll to
Factory Reset.
5. Press
ENTER
to select to
Factory Reset.
Options Menu
Set Clock
Set PWR Save
Set Backlight Time
Factory Reset
12:00:00 001/500
Options Menu
<Enter> Continue
<Exit> to Abort
12:00:00 001/500
30
Page 31
6. Press
Factory Reset. The screen will
momentarily display Writing.
The screen will display Done
and return to the Options
Menu. To retain the current
user level calibration settings,
press
Factory Reset.
ENTER
to complete the
EXIT
to abort the
Options Menu
Done
<Enter> Continue
12:00:00 001/500
Options/Set Up
7. Press
Options Menu.
ENTER
to return to the
Options Menu
Set Clock
Set PWR Save
Set Backlight Time
Factory Reset
12:00:00 001/500
31
Page 32
SELECTING A LANGUAGE
There are seven languages available in the 2020we/wi: English, Spanish,
French, Portuguese, Italian, Chinese, and Japanese (Kana).
1. Press and briefl y hold
to turn the meter on. The
LaMotte logo screen will
Options/Set Up
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 to scroll to Select
Language.
5. Press
ENTER
to select to
Select Language.
Options Menu
Set PWR Save
Set Backlight Time
Factory Reset
Select Language
12:00:00 001/500
Select Language
English
Spanish
French
Portuguese
12:00:00 001/500
32
Page 33
6. Press or to scroll
to desired language.
Select Language
English
Spanish
French
Portuguese
12:00:00 001/500
Options/Set Up
7. Press
ENTER
to select desired
language. The screen
will momentarily display,
Storing...for about 1 second
and return to the Options
Menu.
Set PWR Save aging
Set Backlight Time
Factory Reset
Select Language
12:00:00 001/500
Options Menu
NOTE: If the meter unintentionally switches to another language, use
the procedure above to reset the meter to the desired language. For
example, to reset the meter to English:
1. Turn the meter on.
2. Press down arrow twice. Press ENTER.
3. Press down arrow seven times. Press ENTER.
4. Press ENTER.
33
Page 34
DATA LOGGING
The default setting for the data logger is enabled. The meter will log the
last 500 data points. The counter in the center bottom of the display will
show how many data points have been logged. The display will show
500+ when the data logger has exceeded 500 points and the data
points are being overwritten.
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 Data
Logging.
3. Press
ENTER
to select Data
Logging.
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
Logging
Display Test Log
Enable Logging
Disable Logging
Erase Log
12:00:00 001/500
4. Press
ENTER
to display the last
data point and the time that it
was logged.
Record Number 2
Turbidity - WB (F)
655 AU
12:26:58 PM 08-03-2010
12:00:00 001/500
34
Page 35
5. Press or to scroll
through the data points in the
log.
Record Number 1
Turbidity - WB (F)
95.4 NTU
12:26:44 PM 08-03-2010
12:00:00 001/500
6. Press
EXIT
to return to the
Logging menu. Press
or to scroll to disable
the logging options or erase
the log. Press
ENTER
the option. The screen will
display Storing... for about
1 second and return to the
Logging Menu.
to select
Logging
Display Test Log
Enable Logging
Disable Logging
Erase Log
12:00:00 001/500
Calibration
35
Page 36
CALIBRATION & ANALYSIS
CALIBRATION
Turbidity Standards
Only use AMCO or formazin standards with the 2020we/wi. StablCal
standards below 50 NTU should not be used to calibrate the 2020we/wi.
The diluent used in the StablCal® standards has a different refractive
index than traditional formazin standards and will affect the results.
The concentration of the calibration standard should be similar to the
expected concentration of sample that will be tested. The following
standards are available from LaMotte Company:
1480 0 NTU/FNU Standard, 60 mL (EPA or ISO)
1450 1 NTU Standard, 60 mL (EPA)
1453 1 FNU Standard, 60 mL (ISO)
1451 10 NTU Standard, 60 mL (EPA)
1454 10 FNU Standard, 60 mL (ISO)
Calibration
1452 100 NTU Standard, 60 mL (EPA)
1455 100 FNU Standard, 60 mL (ISO)
Turbidity Calibration Procedure
The default units are NTU and FNU and the default calibration curve
is formazin as indicated by (F) in the Menu bar. A 2020we, which uses
NTU, will be used in the following examples. For the most accurate
results, a user calibration should be performed. The Japan Standard
calibration mode, as indicated by (J) in the Menu bar, should be used
only with Japanese Polystyrene Standards (0-100 NTU). To change the
settings see the Set Up Instructions on page 9.
For the most accurate results, perform a calibration over the smallest
range possible. Use a calibration standard that, along with the blank,
brackets the range of the samples that will be tested. For example, if
the samples that are to be tested are expected to be below 1 NTU, more
accurate results will be obtained by calibration with a blank and a 1 NTU
standard as opposed to a blank and a 100 NTU standard.
®
The meter has fi ve measuring ranges:
0 – 11 NTU/FTU
11 – 110 NTU/FTU
110-300 NTU/FTU
300-600 NTU/FTU
600-4000 NTU/FTU
Each range can be calibrated with one point per range. (Six points
total - a blank plus one point in each of the fi ve ranges - if each range
is calibrated.) New calibration points will replace old calibration points
independently for each range. If one range is recalibrated, the meter will
36
Page 37
retain the old calibration data for the other ranges. It is recommended
that the meter be calibrated for each range that will be used. The value
of the standards chosen for the calibration should not be at the extremes
of the ranges (11, 110, 300, 600 NTU/FTU). The meter is auto-ranging
and will automatically select the appropriate range for the sample being
tested.
It is recommended that the meter be calibrated daily.
1. Press and briefl y hold
to turn the meter on. The
LaMotte logo screen will
appear for about 3 seconds
and the Main Menu will
appear.
2. Press
ENTER
to select
Measure.
3. Press to scroll to
Turbidity - With Blank.
Main Menu
Measure
Data Logging
Options
Run PC Link
12:00:00 001/500
Measure Menu
Turbidity - No Blank
Turbidity - With Blank
12:00:00 001/500
Measure Menu
Turbidity - No Blank
Turbidity - With Blank
12:00:00 001/500
Calibration
4. Press
ENTER
to select
Turbidity - With Blank.
Turbidity WB (F)
Scan Blank
Scan Sample
12:00:00 001/500
37
Page 38
5. Rinse a clean tube (0290)
three times with the blank.
If samples are expected to
read below 1 NTU the meter
should be blanked with a 0
NTU Primary Standard or
prepared turbidity-free (<0.1
NTU) water. For the most
accurate results, use the
same tube for the blank and
the sample.
6. Fill the tube to the fi ll line with
the blank. Pour the blank
down the inside of the tube to
avoid creating bubbles. Cap
Calibration
the tube.
7. Wipe the tube thoroughly with
a lint-free cloth.
l
8. Open the meter lid. Insert the
tube into the chamber. Align
the index line on the tube with
the index arrow on the meter.
Close the lid.
38
Page 39
9. Press
ENTER
to scan the blank.
The screen will display Blank
Done for about 1 second and
then return to the Turbidity -
With Blank Menu.
10. Rinse a clean tube (0290), or
the same tube, three times
with the standard.
11. Fill the tube to the fi ll line
with the standard. Pour the
standard down the inside of
the tube to avoid creating
bubbles. Cap the tube.
Turbidity WB (F)
Scan Blank
Scan Sample
12:00:00 001/500
Calibration
l
12. Wipe the tube thoroughly with
a lint-free cloth.
13. Open the meter lid. Insert the
tube into the chamber. Align
the index line on the tube with
the index arrow on the meter.
Close the lid.
39
Page 40
14. Press
standard. The screen will
display Reading for about 1
second. The result will appear
on the screen.
ENTER
to scan the
Turbidity WB (F)
0.99 NTU
Scan Blank
Scan Sample
12:00:00 001/500
15. Press to scroll to
Calibrate.
Calibration
16. Press
Calibrate. A reverse font
(dark background with light
characters) will appear to
indicate that the reading can
be adjusted.
17. Press or to
scroll to the concentration
of the standard, 1.00 in the
example. Note: The allowable
adjustment is ±20%.
ENTER
to select
Turbidity WB (F)
0.99 NTU
Scan Sample
Calibrate
12:00:00 001/500
Turbidity WB (F)
0.99 NTU
Scan Sample
Calibrate
12:00:00 001/500
Turbidity WB (F)
1.00 NTU
Scan Sample
Calibrate
12:00:00 001/500
18. Press
Caibrate. Two menu
choices will be offered, Set
Calibration and Factory
Setting.
ENTER
to select
Calibrate Menu
1.00 NTU
Set Calibration
Factory Setting
12:00:00 001/500
40
Page 41
19. Press
ENTER
to select Set
Turbidity WB (F)
Calibration and save the
calibration. Press
or
to scroll and select
Factory Setting to revert to
the factory calibration. The
meter will momentarily display
Storing... and return to the
Scan Blank
Scan Sample
12:00:00 001/500
Turbidity -Without Blank
menu. The calibration has
now been saved and the
meter can be used for testing.
NOTE: For the greatest accuracy during the calibration procedure,
be sure that after the meter is blanked and the blank is scanned as a
sample, the reading is 0.00. If not, reblank the meter and scan the blank
again until it reads 0.00. When scanning the calibration standards as
the sample, scan the calibration standard three times removing the
tube from the chamber after each scan and reinserting the tube in the
chamber with the same orientation. The readings should be consistent.
Use the last consistent reading to calibrate the meter. If the readings are
not consistent, avoid using an aberrant reading to calibrate the meter.
ANALYSIS WITHOUT BLANKING PROCEDURE
To obtain the most accurate results the meter should be blanked before
measuring a sample. The blanking step is not as critical for samples
above 10 NTU. The meter should always be blanked before reading
samples below 10 NTU.
Analysis
1. Press and briefl y hold
to turn the meter on. The
LaMotte logo screen will
appear for about 3 seconds
and the Main Menu will
appear.
2. Press
ENTER
to select
Measure.
Main Menu
Measure
Data Logging
Options
Run PC Link
12:00:00 001/500
Measure Menu
Turbidity - No Blank
Turbidity - With Blank
12:00:00 001/500
41
Page 42
3. Press
ENTER
to select
Turbidity - No Blank.
4. Rinse a clean tube (0290)
three times with the sample.
5. Fill the tube to the fi ll line with
the sample. Pour the sample
down the inside of the tube to
avoid creating bubbles. Cap
the tube.
Turbidity NB (F)
Scan Blank
Scan Sample
12:00:00 001/500
l
Analysis
6. Wipe the tube thoroughly with
a lint-free cloth.
7. Open the meter lid. Insert the
tube into the chamber. Align
the index line on the tube with
the index arrow on the meter.
Close the lid.
42
Page 43
8. Press
Sample. The screen will
display Reading for about 1
second. The result will appear
on the screen.
ANALYSIS WITH BLANKING PROCEDURE
To obtain the most accurate results the meter should be blanked before
measuring a sample. The blanking step is not as critical for samples
above 10 NTU. The meter should always be blanked before reading
samples below 10 NTU.
ENTER
to select Scan
10.22 NTU
Scan Blank
Scan Sample
12:00:00 001/500
Turbidity NB (F)
1. Press and briefl y hold
to turn the meter on. The
LaMotte logo screen will
appear for about 3 seconds
and the Main Menu will
appear.
2. Press
Measure.
3. Press to scroll to
Turbidity - With Blank.
ENTER
to select
Main Menu
Measure
Data Logging
Options
Run PC Link
12:00:00 001/500
Measure Menu
Turbidity - No Blank
Turbidity - With Blank
12:00:00 001/500
Measure Menu
Turbidity - No Blank
Turbidity - With Blank
Analysis
43
Page 44
4. Press
ENTER
to select
Turbidity - With Blank.
5. Rinse a clean tube (0290)
three times with the blank.
If samples are expected to
read below 1 NTU the meter
should be blanked with a 0
NTU Primary Standard or
prepared turbidity-free (<0.1
NTU) water. For the most
accurate results, use the
same tube for the blank and
the sample.
6. Fill the tube to the fi ll line with
the blank. Pour the blank
down the inside of the tube to
avoid creating bubbles. Cap
the tube.
Turbidity WB (F)
Scan Blank
Scan Sample
12:00:00 001/500
l
Analysis
7. Wipe the tube thoroughly with
a lint-free cloth.
44
Page 45
8. Open the meter lid. Insert the
tube into the chamber. Align
the index line on the tube with
the index arrow on the meter.
Close the lid.
9. Press
ENTER
to scan the blank.
The screen will display Blank
Done for about 1 second and
then return to the Turbidity -
With Blank menu.
10. Rinse a clean tube (0290), or
the same tube, three times
with the sample.
11. Fill the tube to the fi ll line
with the standard. Pour the
standard down the inside of
the tube to avoid creating
bubbles. Cap the tube.
Turbidity WB (F)
Scan Blank
Scan Sample
12:00:00 001/500
l
Analysis
12. Wipe the tube thoroughly with
a lint-free cloth.
45
Page 46
13. Open the meter lid. Insert the
tube into the chamber. Align
the index line on the tube with
the index arrow on the meter.
Close the lid.
14. Press
standard. The screen will
display Reading for about 1
second. The result will appear
on the screen.
NOTE: The meter will remember the last scanned blank reading. It is not
necessary to scan a blank each time the test is performed. To use the
previous blank reading, instead of scanning a new one, scroll to Scan
Sample and proceed. For the most accurate results, the meter should
be blanked before each test and the same tube should be used for the
blank and the reacted sample.
DILUTION PROCEDURES
If a sample is encountered that is more than 4000 NTU or FNU, a careful
dilution with 0 NTU/FNU or very low turbidity water will bring the sample
into an acceptable range. However, there is no guarantee that halving
Analysis
the concentration will exactly halve the NTU or FNU value. Particulates
often react in an unpredictable manner when diluted.
Turbidity-Free Water
The defi nition of low turbidity and turbidity-free water has changed as
fi lter technology has changed and nephelometric instruments have
become more sensitive. At one time turbidity-free water was defi ned as
water that had passed through a 0.6 micron fi lter. Now 0.1 micron fi lters
are available and higher purity water is possible. Water that has been
passed through a 0.1 micron fi lter could be considered particle free and
therefore turbidity free, 0 NTU water. Turbidity is caused by scattered
light. Therefore, low turbidity water is water without any particles that
scatter a measurable amount of light. But water that passed through
a 0.1 micron fi lter may still have detectable light scatter with modern
instruments. This light scattering can be the result of dissolved
molecules or sub-micron sized particles that can not be fi ltered out of
the water. Because there may still be a small amount of scattered light
from dissolved molecules, high purity water is often called low turbidity
water and assigned a value of 0.01 or 0.02 NTU. However, because this
water is used as a baseline to compare to sample water, the difference
between the sample and the low turbidity or turbidity-free water will
ENTER
to scan the
0.99 NTU
Scan Blank
Scan Sample
12:00:00 001/500
Turbidity WB (F)
46
Page 47
be the same whether it is called 0.00 NTU or 0.02 NTU. For design
simplicity the 2020we/wi uses the term turbidity-free water and the value
of 0.00 NTU.
PREPARATION OF TURBIDITY-FREE WATER
A 0 NTU/FNU Standard (Code 1480) is included with the meter. An
accessory package (Code 4185) is available for preparing turbidity-free
water for blanking the meter and dilution of high turbidity samples.
The preparation of turbidity-free water requires careful technique.
Introduction of foreign matter will affect the turbidity reading. A fi ltering
device with a special membrane fi lter is used to prepare turbidity-
free water. The fi lter, fi lter holder and syringe must be conditioned
by forcing at least two syringes full of deionized water through the
fi ltering apparatus to remove foreign matter. The fi rst and second
rinses should be discarded. Turbidity-free water as prepared with the
following procedure may be stored in the dark at room temperature in a
clean glass bottle with a screw cap and used as required. The storage
container should be rinsed thoroughly with fi ltered deionized water
before fi lling. The water should be periodically inspected for foreign
matter in bright light.
1. Remove the plunger from
the syringe (0943). Attach
the fi lter to the bottom of the
syringe.
Analysis
2. Pour approximately 50 mL
of deionized water into the
barrel of the syringe. Insert
the plunger. Exert pressure
on the plunger to slowly force
the water through the fi lter.
Collect water in the clean
storage container. Rinse walls
of the container then discard
this rinse water.
47
Page 48
3. Remove the fi lter from the
syringe. Remove the plunger
from the barrel. (This step is
required to prevent rupturing
the fi lter by the vacuum that
would be created when the
plunger is removed.)
4. Replace the fi lter and repeat
step 2 for a second rinse
of the syringe and storage
container.
5. Remove the fi lter from the
syringe. Remove the plunger
from the barrel. Replace
the fi lter and fi ll the syringe
with approximately 50 mL
of deionized water. Filter
the water into the storage
container and save this
Analysis
turbidity-free water.
6. Repeat Step 5 until the
desired amount of turbidityfree water has been collected.
TESTING TIPS
1. Samples should be collected in a clean glass or polyethylene
container.
2. Samples should be analyzed as soon as possible after collection.
3. Gently mix sample by inverting before taking a reading but avoid
introducing air bubbles.
4. For the most precise results, follow the recommended procedure
48
Page 49
for wiping a fi lled tube before placing it in the meter chamber. Invert
tube very slowly and gently three times to mix the sample. Surround
the tube with a clean, lint-free cloth. Press the cloth around the tube.
Rotate the tube in the cloth three times to assure that all areas of the
tube have been wiped.
5. Discard tubes that have signifi cant scratches and imperfections in
the light pass zones. (Central zone between bottom and fi ll line).
6. When reading very low turbidity samples, do not use tubes or caps
that have been used previously with high turbidity samples.
7. Use the averaging option for low level measurements of turbidity.
8. The meter should be placed on a surface that is free from vibrations.
Vibrations can cause high readings.
9. Turbidity readings will be affected by electric fi elds around motors.
10. Carbon in the sample will absorb light and cause low readings.
11. Excessive color in a sample will absorb light and cause low
readings. The user should verify if a certain level of color will cause a
signifi cant error at the level of turbidity being tested.
12. Observe shelf life recommendations for turbidity standards.
13. Do not use silicone oil on tubes when testing turbidity with the
2020we/wi.
14. When testing at low concentrations use the same tube for the blank
and the sample.
15. Always insert tube into the meter chamber with the same amount of
pressure and to the same depth.
16. Occasionally clean the chamber with a damp lint-free wipe, followed
by a Windex
®
dampened wipe. A clean chamber and tubes are
essential for reliable results.
17. For the greatest accuracy during the calibration procedure, be
sure that after the meter is blanked and the blank is scanned as
a sample, the reading is 0.00. If not, reblank the meter and scan
the blank again until it reads 0.00. When scanning the calibration
standards as the sample, scan the calibration standard three times
removing the tube from the chamber after each scan. The readings
should be consistent. Use the last consistent reading to calibrate
the meter. If the readings are not consistent, avoid using an aberrant
reading to calibrate the meter.
18. Calibrate the meter daily.
19. Calibrate the meter with a standard that is closest to the expected
range of the sample being tested. For example, if the sample
is expected to be less than 1.0 NTU, calibrate with a 1.0 NTU
standard and a blank (0 NTU standard). If the sample is expected
to be around 2 NTU also calibrate with the 1.0 NTU standard but
if the sample is expected to be around 8 NTU calibrate with a 10
NTU standard. If the sample is expected to be over 30 – 40 NTU
it is recommended that the meter be calibrated with a 100 NTU
standard.
49
Page 50
TROUBLESHOOTING GUIDE
TROUBLESHOOTING
PROBLEM REASON SOLUTION
“Blank?” Sample is reading
lower than the blank.
Flashing
“Low Battery” Battery voltage is very
“Shut Down Low
Batt” Shut Down
“Over range” Sample is outside of
Low battery. Readings
are reliable.
low. Readings are not
reliable.
Battery is too low to
operate the unit.
acceptable range.
With samples of very
low concentration
reblank or record as
zero. On samples of
higher concentration
reblank and read again.
Charge battery or use
USB wall/computer
charger.
Charge battery or use
USB wall/computer
charger.
Charge battery or use
USB wall/computer
charger.
Dilute sample and test
again.
“Error1” High readings
with 90° and 180°
detectors.
Lost in meter menus Reset to factory
default settings.
Unusually large
negative or
positive readings
when performing
calibration
STRAY LIGHT
The accuracy of readings on the 2020we/wi should not be affected by
stray light. Make sure that the sample compartment lid is always fully
closed when taking readings. The backlight will interfere with turbidity
readings. The meter will temporarily disable the backlight while turbidity
measurements are being taken.
Incorrect standards
used to calibrate
meter.
50
Dilute sample by at
least 50% and retest.
Follow Procedure on
page 9 or page 26.
Use fresh 0.0 standard
in clean tube. Reset
meter to factory default
settings. Recalibrate
meter.
Page 51
GENERAL OPERATING INFORMATION
OVERVIEW
The 2020we/wi is a portable, microprocessor controlled, direct reading
nephelometer. Turbidity is measured directly by either EPA Method 180.1
or ISO Method 7027. It has a graphical liquid crystal display and six
button keypad. These allow the user to select options from the menu
driven software, to directly read test results or to review stored results of
previous tests in the data logger. The menus can be displayed in seven
different languages.
The 2020we/wi uses a state of the art, multi-detector optical
confi guration that assures long term stability of calibrations, high
precision and accuracy and low detection limits. All readings are
determined by sophisticated digital signal processing algorithms,
minimizing fl uctuations in readings and enabling rapid, repeatable
measurements. The microprocessor and optics enable a dynamic range
and auto-ranging over several ranges. Energy effi cient LED light sources
are used for ISO turbidity. EPA turbidity uses a tungsten fi lament light
source that meets or exceeds EPA specifi cations and is designed for a
uniform light spot image and stable output.
A USB wall adapter, USB computer connection or lithium battery powers
the 2020we/wi.
A USB port on the back of the meter allows an interface of the meter
with a Windows-based computer for real-time data acquisition and
data storage using a PC. The 2020we/wi may be interfaced with any
Windows-based computer by using the LaMotte SMARTLink 3 Program.
GENERAL OPERATING INFORMATION
The operation of the 2020we/wi is controlled by the menu driven
software and user interface. A menu is a list of choices. This allows a
selection of various tasks for the 2020we/wi to perform, such as, scan
blank and scan sample. The keypad is used to make menu selections
that are viewed on the display.
51
Page 52
The Keypad
This button will scroll up through a list of menu selections.
ENTER
The button is used to select choices in a menu viewed in
the display.
This button controls the backlight on the display.
This button will scroll down through a list of menu
selections.
EXIT
This button exits to the previous menu.
This button turns the meter on or off.
ENTER
EXIT
THE DISPLAY & MENUS
The display allows menu selections to be viewed and selected. These
selections instruct the 2020we/wi to perform specifi c tasks. The menus
are viewed in the display using two general formats that are followed
from one menu to the next. Each menu is a list of choices or selections.
The display has a header line at the top and a footer line at the bottom.
The header displays the title of the current menu. The footer line
displays the time and the date, the data logger status and the battery
status. The menu selection window is in the middle of the display
between the header and the footer.
The menu selection window displays information in two general formats.
In the fi rst format only menu selections are displayed. Up to 4 lines of
menu selections may be displayed. If more selections are available they
can be viewed by pressing the arrow buttons
to scroll the
other menu selections into the menu selection window. Think of the
menu selections as a vertical list in the display that moves up or down
each time an arrow button is pressed. Some menus in the
2020we/wi are looping menus. The top and bottom menu choices are
connected in a loop. Scrolling down past the bottom of the menu will
lead to the top of the menu. Scrolling up past the top of the menu will
lead to the bottom of the menu.
52
Page 53
Header Menu Title
Main Selection Window
Footer
A black bar will indicate the menu choice. As the menu is scrolled
through, the black bar will highlight different menu choices. Pressing the
ENTER
button will select the menu choice that is indicated by the black
bar.
In the second format the menu choice window takes advantage of the
graphical capabilities of the display. Large format graphic information,
such as test results or error messages or the LaMotte logo is displayed.
The top two lines of the display are used to display information in
a large, easy to read format. The menus work in the same way as
previously described but two lines of the menu are visible at the bottom
of the display.
First Choice
Second Choice
Third Choice
Another
12:00:00 001/500
And Another
And So On
Header Menu Title
Message or Result Window
Result or
Message
Another
Main Selection Window And Another
Footer
As described previously, the
the current menu and a return to the previous menu. This allows a rapid
exit from an inner menu to the main menu by repeatedly pushing the
EXIT
button. Pushing at any time will turn the 2020we/wi off.
EXIT
12:00:00 001/500
And So On
Last Choice
button allows an exit or escape from
53
Page 54
The display may show the following messages:
Battery Status
More choices are available and can be viewed by
scrolling up and/or down through the display.
Header Identifi es the current menu and information on units
and reagent systems if applicable.
Footer In the data logging mode the number of the data point
is displayed and the total number of data points in the
memory will be shown. The footer also shows current
time and battery status
NEGATIVE RESULTS
There are always small variations in readings with analytical instruments.
Often these variations can be observed by taking multiple readings of
the same sample. These variations will fall above and below an average
reading. Repeated readings on a 0.00 sample might give readings
above and below 0.00. Therefore, negative readings are possible and
expected on samples with concentrations at or near zero. This does
not mean there is a negative concentration in the sample. It means
the sample reading was less than the blank reading. Small negative
readings can indicate that the sample was at or near the detection limit.
This is a normal variation that results in a negative reading. A large
negative reading, however, is not normal and indicates a problem.
Some instruments are designed to display negative readings as zero.
In this type of instrument, if the meter displayed zero when the result
was actually a large negative number there would be no indication that
a problem existed. For this reason, the 2020we/wi displays negative
numbers for turbidity.
TUBES AND CHAMBERS
The 2020we/wi uses one type of tube (Code 0290). There is no need for
a special turbidity tube.
The handling of the tubes is of utmost importance. Tubes must be clean
and free from lint, fi ngerprints, dried spills and signifi cant scratches,
especially the central zone between the bottom and the sample line.
Scratches, fi ngerprints and water droplets on the tube can cause stray
light interference leading to inaccurate results when measuring turbidity.
Scratches and abrasions will affect the accuracy of the readings. Tubes
that have been scratched in the light zone through excessive use should
be discarded and replaced with new ones.
Tubes should always be washed on the inside and outside with mild
54
Page 55
detergent prior to use to remove dirt or fi ngerprints. The tubes should be
allowed to air-dry in an inverted position to prevent dust from entering
the tubes. Dry tubes should be stored with the caps on to prevent
contamination.
After a tube has been fi lled and capped, it should be held by the cap
and the outside surface should be wiped with a clean, lint-free absorbent
cloth until it is dry and smudge-free. Handling the tube only by the cap
will avoid problems from fi ngerprints. Always set the clean tube aside
on a clean surface that will not contaminate the tube. It is imperative that
the tubes and light chamber be clean and dry. The outside of the tubes
should be dried with a clean, lint-free cloth or disposable wipe before
they are placed in the meter chamber.
Tubes should be emptied and cleaned as soon as possible after reading
a sample to prevent deposition of particulates on the inside of the tubes.
When highly accurate results are required, reduce error by designating
tubes to be used only for very low turbidity and very high turbidity
testing.
Variability in the geometry of the glassware and technique is the
predominate cause of variability in results. Slight variations in wall
thickness and the diameter of the tubes may lead to slight variations in
the test results. To eliminate this error the tubes should be placed in the
chamber with the same orientation each time.
Chambers which have been scratched through excessive use should be
discarded and replaced with a new one.
MAINTENANCE
CLEANING
Clean the exterior housing with a damp, lint-free cloth. Do not allow
water to enter the light chamber or any other parts of the meter. To clean
the light chamber and optics area, point a can of compressed air into
the light chamber and blow the pressurized air into the light chamber.
Use a cotton swab dampened with Windex
®
window cleaner to gently
swab the interior of the chamber. Do not use alcohol; it will leave a thin
residue over the optics when dry.
REPAIRS
Should it be necessary to return the meter for repair or servicing,
pack the meter carefully in a suitable container with adequate packing
material. A return authorization number must be obtained from LaMotte
Company by calling 800-344-3100 (US only) or 410-778-3100, faxing
410-778-6394, or emailing tech@lamotte.com. Often a problem can
be resolved over the phone or by email. If a return of the meter is
necessary, attach a letter with the return authorization number, meter
serial number, a brief description of problem and contact information
55
Page 56
including phone and FAX numbers to the shipping carton. This
information will enable the service department to make the required
repairs more effi ciently.
METER DISPOSAL
Waste Electrical and Electronic Equipment (WEEE)
Natural resources were used in the production of this equipment. This
equipment may contain materials that are hazardous to health and the
environment. To avoid harm to the environment and natural resources,
the use of appropriate take-back systems is recommended. The crossed
out wheeled bin symbol on the meter encourages the use of these
systems when disposing of this equipment.
Take-back systems will allow the materials to be reused or recycled
in a way that will not harm the environment. For more information on
approved collection, reuse, and recycling systems contact local or
regional waste administration or recycling services.
56
Page 57
575859
Page 58
Page 59
Page 60
802 Washington Ave • Chestertown • Maryland • 21620 • USA
410-778-3100 • 800-344-3100
www.lamotte.com
1970-MN • 02.01.12
Loading...