Apera TN400 User manual

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TN400 Portable Turbidity Meter
Instruction Manual
APERA INSTRUMENTS LLC
www.aperainst.com

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Table of Contents
1Overview...................................................................................................... - 3 -
2Technical Specifications ................................................................................ - 4 -
2.1 Technical Parameters.................................................................................................- 4 -
2.2 Others.......................................................................................................................- 4 -
3Instrument Description................................................................................. - 5 -
3.1 Instrument Overview ................................................................................................- 5 -
3.2 Meter and Accessories ..............................................................................................- 6 -
3.3 Display......................................................................................................................- 7 -
3.4 Keypad......................................................................................................................- 7 -
3.5 Battery Installation....................................................................................................- 8 -
4Meter Calibration ......................................................................................... - 8 -
4.1 Calibration Standards ................................................................................................- 9 -
4.2 Calibration Procedure................................................................................................- 9 -
4.3 Calibration Notes ....................................................................................................- 10 -
5Turbidity Measurement.............................................................................. - 11 -
5.1 Sample Vial Handling...............................................................................................- 11 -
5.2 Measurement Preparation ...................................................................................... - 11 -
5.3 For Single Measurement..........................................................................................- 12 -
5.4 For Continuous Measurement .................................................................................- 12 -
5.5 Measurement Notes................................................................................................- 12 -
6Warranty.................................................................................................... - 15 -

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1 OVERVIEW
Thank you for selecting our portable TN400 turbidity meter.
This meter is an outstanding combination of the most advanced electronic
technology and software design, and is the most cost-effective portable
turbidity meter. This meter operates on the nephelometric principle of turbidity
measurement and is designed to meet the criteria specified in ISO7027 and
DIN 27027 standards. TN400 allows you to measure the turbidity of an
aqueous sample both in laboratory and in the field.
With built-in microprocessor chips, elegant design, easy to use, the meter has
the following remarkable characteristics:
Smart functions, such as automatic calibration, operating instructions,
automatic power-off, low voltage display and etc.
Large TFT color screen, with blue background in measuring mode, green
background in calibration mode, and text and graphics in operational
directive.
With advanced digital processing technology, the accuracy of the meter is
greatly improved.
The structure design meets the requirements of IP67 level of protection and
is suitable
for use in field and on-site.
Contained in customized portable case, calibration standards, sample vials
and other
necessary accessories are more convenient to use and carry.

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2 TECHNICAL SPECIFICATIONS
2.1 Technical Parameters
Measuring Method
ISO 7027 compliant nephelometric method（90°）
Measuring Range
0 to 1000 NTU, automatic range selection:
0.01 to 19.99 NTU
20.0 to 99.9 NTU
100 to 1000 NTU
Resolution
0.01 / 0.1 / 1 NTU
Reading Error
≤ ±2 % of reading±stray light
Repeatability
≤ ±1% of reading or 0.02 NTU, whichever is greater
Calibration
Standards
0.02 NTU, 20.0 NTU, 100 NTU, 800 NTU(Polymer)
Light Source
Infrared light emitting diode（850nm wavelength）
Detector
Silicon photovoltaic
Display
TFT Color screen
Sample Vials
Φ25×60 mm, high borosilicate glass with screw cap
Sample Volume
18 ml
Operating Temp.
Range
0 to 50°(32˚F to 122˚F)
2.2 Others
Power Supply
4× AA Alkaline Batteries
IP Rating
IP67
Dimension/Weight
Meter：(90×203×80)mm / 385 g
Portable Case：(310×295×110)mm / 1.5 kg
Quality and Safety
Certificate
ISO9001:2008 & CE

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3 INSTRUMENT DESCRIPTION
3.1 Instrument Overview
①
Housing
⑥
Sampling well
②
Flip cover of the sampling well
(Close the cover when
measuring)
⑦
Calibration vials or sample vials
③
Display
⑧
Positioning mark (Align the mark
with the mark on the calibration
vial or the sample vial)
④
Keypad
⑨
Battery cover
⑤
Dust proof plug (Take off the plug
when measuring)
Diagram-1

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3.2 Meter and Accessories
①
Standard solution: 0.02NTU,
20.0NTU, 100NTU, 800 NTU
⑥
Silicon oil (10 ml)
②
Portable case
⑦
Sample vial×3
③
TN400 Meter
⑧
Screwdriver (to remove
battery cover)
④
Soft cloth
⑨
Instruction manual
⑤
“AA” Alkaline battery×4
Diagram-2
①
②
③
④
⑤
⑥
⑦
⑧
⑨

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3.3 Display
Measuring Mode
Calibration Mode
Calibration Menu Mode
3.4 Keypad
Diagram- 3
①— Measuring mode icon
②— reading/Unit
③— Progress bar
④— Operational directive
⑤— Low battery display
①— Calibration mode icon
②— Reading/Unit
③— Progress bar
④— Operational directive
①— Calibration mode Icon
②— Standard solution value
③— Operational directive

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Key
Functions
Power on/off
The meter will automatically shut off 10 mins after last key
press
 Initiate /Exit the calibration mode
In measuring mode：Short press the key to perform single-
shot
measurement; long press the key to perform continuous
measurement.
In calibration mode: press the key to confirm the calibration.
In calibration mode, press the key to select standard
solution.
3.5 Battery Installation
1. Use the screwdriver to remove the four screws on the battery cover and
open the battery cover.
2. Insert 4 pieces of AA alkaline battery. Please make sure the polarity is
correct.
3. Put on the battery cover and screw tightly.
4 METER CALIBRATION
TN400 turbidity meter needs to be calibrated with the provided standard
solution when used for the first time. For normal use, it is suggested to calibrate
the meter monthly or weekly depending on the frequency of use; or the user
can perform verification test, which is to test the standard solution that is close
to the value of the test sample. If the error is big, it is necessary to calibrate the
meter. To ensure the accuracy, 4 polymer standards included in the meter kit
should be selected to calibrate the meter.

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4.1 Calibration Standards
TN400 turbidity meter adopts US EPA certified Reagecon high molecular
weight polymer turbidity standard solution. Compared with traditional Formazin
standard solution, Reagecon standard solution has a lot of advantages, such
as non-toxicity, high accuracy, long shelf-life, traceable to NIST and so on. The
standard solution supplied in the TN400 turbidity meter kit has a shelf-life of 12
months (from the date of manufacture). Please check the date on the bottom
of the vials before using.
4.2 Calibration Procedure
1）Apply a little silicone oil on the
calibration vial and wipe with the soft
cloth to obtain an even distribution.
Turn the vial of 20.0, 100, 800 NTU
upside down several times and set it
still for 2 mins.(0.02 NTU doesn’t
need to be overturned)
2) Press key to turn on the
meter. The meter indicates
measuring mode.
3) Open the flip cover and put in
0.02NTU calibration vial. Align the
mark on the vial with the mark on
the sample well and then close the
cover.
4) Press key to enter into
calibration menu, and press
key to perform calibration when
cursor indicates on 0.02NTU.
5) After calibration with 0.02NTU
standard, press key to
return to calibration menu.
6) When cursor indicates on
20.0NTU, put the calibration vial of
20.0 NTU into the sample well and
press key to calibrate.

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7) After calibration with 20.0 NTU
standard, press key to
return to calibration menu.
8) When cursor indicates on
100NTU, put the calibration vial of
100NTU into the sample well and
press key to calibrate.
9) After calibration with 100 NTU
standard, press key to
return to calibration menu.
10) When cursor indicates on
800NTU, put the calibration vial of
800 NTU into the sample well and
press key to calibrate.
11) After calibration with 800 NTU
standard, press key to
confirm.
12) The meter enters measuring
mode.
4.3 Calibration Notes
1) Place turbidimeter on a flat and level surface,
and please do not hold the instrument in hand.
2) When a calibration vial is placed into measuring well, the arrow
mark on vial cap must be aligned with the arrow mark on
the measuring well. See diagram-4
3) Apply 1-2 drops of silicone oil on the calibration vial and
wipe even with soft cloth to improve light scattering. After wiping and
cleaning, set the calibration vial still on the table for at least 2 minutes to
eliminate micro bubble in solution. For 0.02 NTU calibration vial, the standing
time should be at least 5 minutes.
4) Please perform 4 points calibration for first time use according to clause
4.3. 2 to 4 points of calibration can be selected for subsequent use
according to requirement. Better result is obtained if it is in the range of
the above two points. When calibrating, press
or to select calibration standard. After calibrating, press
button to quit and enter measurement mode.
Diagram- 4

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5) If Formazin standard is used to calibrate, note the diluted Formazin
standard is not stable. Please make sure to use new prepared Formazin
standard to ensure calibration precision.
6) Please do not open the cap of calibration vial. Inspect the expiration of
calibration standard. Make sure the calibration vial free from dust, dirt,
fingerprint and scratch.
7) Please use the same method to calibrate every time, and establish
standard operating procedures (SOPs).
5 TURBIDITY MEASUREMENT
5.1 Sample Vial Handling
1) There are 3 sample vials contained in the case, marked 1#, 2# and 3# on
the cap and bottom of the vial. Please note the number of sample vial
should be same as that of vial cap, and do not mix up.
2) Sample vial has been meticulously cleaned and disinfected. It can be used
directly for the first time. Before subsequent uses, sample vial should be
thoroughly cleaned: wash the interior and exterior of the vial in a detergent
solution repeatedly rinse with clean distilled water or deionized water.
Rinse sample vial with sample solution twice fill sample vial with
sample solution screw the vial cap tightly.
5.2 Measurement Preparation
1) Collect sample solution in a clean vessel, fill sample solution
to the
4/5 position of sample vial (approximately 18ml), see
diagram-5, screw the vial cap tightly.
2) Before measuring, please make sure sample solution is uniform.
Gently shake the sample vial to make sample solution uniform, and wait
until air bubbles disappear.
3) Wipe the sample vial surface with the soft cloth. Ensure that the outside of
the vial is dry, clean and free from smudges.
4) Apply 1 to 2 drops of silicone oil on the surface of the vial. Wipe with a soft
cloth to obtain an even distribution over the entire surface in order to
Diagram- 5

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ameliorate scratches and flaws and improve light scattering.
5) Place turbidimeter on a flat and level surface, please do not handheld the
instrument.
6) Hold vial cap, align the arrow mark on vial cap with the arrow mark on the
calibration well, and insert sample vial into the measuring well and close
the cover
5.3 For Single Measurement
Press button, the display shows progress
bar(see diagram-6). It will display measured value
after 8 seconds. Please press button again for
repeated measurement.
5.4 For Continuous Measurement
1) Press and hold button, release it until the display
shows the wire frame of progress bar(see diagram-7).
The
instrument enters continuous measuring mode. The
display is updated every 8 seconds with continuous measurements
and display. Press button again to exit and then the
instrument enters single measurement mode.
2) Continuous measuring mode can be used to observe the process of
stabilizing turbidity values. It’s also suitable for a sample solution which
precipitates faster, since it records every measuring value and calculates
the average value.
5.5 Measurement Notes
Turbidity is a very complex analytical measurement which can be affected
by many factors. Some are inherent in the design of instrument. However,
there are also other factors such as stray light, air bubbles, vial handling
and other operating technique.
1) Sample Vial
Sample vial must be meticulously cleaned and free from spots and
scratches. Its surface should be applied with some silicone oil to treat the
outside with a uniform thin coating. This is to mask minor imperfections
Diagram-6
Diagram-7

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and scratches that may contribute to stray light. Do not apply large quantity
of oil as this may collect dirt and dust and extra oil should be wiped off with
soft cloth. When wiping, user should grip the cap to avoid leaving
fingerprints on the surface of glass vial.
2) Silicone Oil
The refractive index of silicone oil should be same with that of glass vial.
It is
recommended to use silicone oil supplied with the instrument.
3) Match Sample Vials
Instrument is supplied with 3 sample vials which were optically matched
when they are manufactured, so they have good consistency. If user needs
to purchase more sample vials, please order a set of 3 pieces. Or user can
perform optical match by himself, and the method is described as follows:
clean the sample vial, fill about 0.5 NTU pure water or distilled water into
vial. After cleaning the surface of vial, set aside for more than 5 minutes to
eliminate air bubbles. For each vial, rotate 8 different angles, measure,
collect data from 8 observations and record it. Find the position of these
vials where the values of measurement are the closest and mark it.
4) Mixing and Degassing
Samples should not be violently shaken or agitated. It is recommended
user gently shake sample vial to make solution uniform. Air bubbles in
solution will cause big error to turbidity measurement. So air bubble must
be eliminated before measuring. But mixing and degassing simultaneously
is a difficult process to handle, especially for solution with precipitates,
which requires some operating experience and experimental conditions.
For example, same mixing condition and equilibrating time for degassing
are required for two measurements to be comparable.
5) Low Turbidity Measurement
To measure sample with very low turbidity (<1 NTU), it’s better to use the
same sample vial to do calibration and testing. This can offer the best
accuracy and repeatability. For details, please follow the steps below:
a) Take a sample vial (for example, 1#), use distilled water (not tap water
or mineral water) to rinse the sample vial. Then pour distilled water to
the sample vial, screw on the cap, and let the vial stand still for 3
minutes. In the meantime, turn over the 20.0 NTU calibration vial back
and forth 5 times, and let it stand still for 3 minutes.

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b) Use 1# sample vial to calibrate 0.02 NTU; Use 20.0 NTU calibration
vial to calibrate 20 NTU.
c) Dump the distilled water in 1# vial, and dry the vial (using a dryer).
Pour your tested sample solution into the 1# vial; Screw on the cap
and let it stand still for 3 minutes; Take measurements.
6) Other Requirements
a) On the premise of ensuring uniform sample, sample should be
measured immediately to prevent temperature changing and
precipitates from affecting measuring values.
b) Avoid the sample dilution for measurement as much as possible.
c) Avoid operating under direct sunlight.
d) Do not pour solution into measuring well. Sample vial must be used for
measurement.
e) Please do not try to wash the measuring well as this may damage its
optical structure.

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6 WARRANTY
We warrant this instrument to be free from defects in material and workmanship
and agrees to repair or replace free of charge, at option of APERA
INSTRUMENTS, LLC, any malfunctioned or damaged product attributable to
responsibility of APERA INSTRUMENTS, LLC for a period of two years from
the delivery (a six-month limited warranty applies to the calibration solutions).
This warranty does not apply to defects resulting from actions such as misuse
(violation of the instructions in this manual or operations in the manner not
specified in this manual), improper maintenance, or unauthorized repairs.
Warranty period is the time limit to provide free service for the products
purchased by customers, not the service life of the product.

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APERA INSTRUMENTS, LLC
Address: 977 Old Henderson Rd, Columbus, Ohio 43220
Tel: [phone]
Email: [e-mail]
Website: www.aperainst.com