Apera Instruments WS100 User manual

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WS100 Fluoride/pH Portable Meter Kit
Instruction Manual
APERA INSTRUMENTS (Europe) GmbH
www.aperainst.de

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Inhalt
APERA INSTRUMENTS (Europe) GmbH.......................................................................................- 1 -
1Overview .............................................................................................................................- 3 -
1.1 Basic Functions......................................................................................................................... - 3 -
1.2 Features of Fluoride Measurement .......................................................................................... - 3 -
1.3 Features of pH measurement ................................................................................................... - 3 -
2Technical Parameters：.......................................................................................................- 4 -
2.1 Fluoride .................................................................................................................................... - 4 -
2.2 pH............................................................................................................................................. - 4 -
2.3 mV：........................................................................................................................................ - 4 -
2.4 Other technical parameters:..................................................................................................... - 4 -
3Instrument Description........................................................................................................- 5 -
3.1 LCD Display：........................................................................................................................... - 5 -
3.2 Operation keys ......................................................................................................................... - 5 -
3.3 Memory Storage, Recall Memory, and Clear Memory: 3.3.1 Memory Storage......................... - 6 -
4Fluoride concentration measurement .................................................................................- 7 -
4.1 Preparation............................................................................................................................... - 7 -
4.2 Calibration ................................................................................................................................ - 7 -
4.3 Sample Measuring.................................................................................................................... - 8 -
4.4 Parameter Settings ................................................................................................................... - 8 -
4.5 Special Notes ............................................................................................................................ - 8 -
5pH Measurement.................................................................................................................- 9 -
5.1 Preparing the Meter ................................................................................................................. - 9 -
5.2 Meter Calibration ..................................................................................................................... - 9 -
5.3 Sample Test ............................................................................................................................ - 11 -
5.4 Parameter Settings ................................................................................................................. - 11 -
5.5 Special Notes .......................................................................................................................... - 14 -
5.6 Self-diagnose Information ...................................................................................................... - 16 -
6mV Measurement.............................................................................................................. - 17 -
6.1 Sample Test ............................................................................................................................ - 17 -
7Complete Kit ...................................................................................................................... - 17 -
8Warranty............................................................................................................................ - 17 -
9Appendix 1. Fluoride Concentration Conversion Table ...................................................... - 18 -

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1Overview
Thank you for purchasing the Apera Instruments WS100 Fluoride/pH Portable Meter Kit (Hereon
after referred as the meter). This fluoride/pH combo meter is widely used for drinking water, surface
water and other water treatment applications, ideal for both in-field and laboratory testing.
Before using the product, please read this manual carefully before use to help you properly use and
maintain the instrument.
For technical support, please contact us at [e-mail] or [phone]
1.1 Basic Functions
Automatic calibration and temperature compensation (ATC), data storage, self-
diagnostics, automatic shutdown, low-battery reminder
Adopting digital filtering and intelligence to improve the instrument's responsiveness and
accuracy of measurement data, measured value display when stable " " Icon.
Meets IP57 Waterproof and dustproof rating, ideal for use under harsh environment.
1.2 Features of Fluoride Measurement
Patented structure of the 3-in-1 ion electrode contains: ion-selective electrode, reference
electrode, and temperature electrode. This design generates quick stability, fast response,
and is easy to use.
no need for stirring or added reagents, directly measuring the ion concentration of fluoride in
a quick and simple manner, directly measure the fluoride concentration with three different
units: mg/L, ppm and pF.
1.3 Features of pH measurement
1-3 points of automatic calibration, with calibration icons and self diagnosis function.
Automatic recognition of up to 12 different pH standard buffer solutions, there are three
series of standard buffer solutions to choose from: U.S.A, NIST, and China.

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2Technical Parameters：
2.1 Fluoride
Measuring range 0.02 ppm to 1900 ppm
Display units mg/L, ppm, pF
Accuracy ±0.02 ppm or ±5% of reading (which ever is greater)
Temperature
Compensation Range ( 0-80 ) ℃( Automatic)
2.2 pH
Measuring range ( -2.00 - 19.99 ) pH
Resolution 0.1/0.01 pH
Accuracy ± 0.01 pH ± 1 digit
Temperature Compensation Range ( 0 - 100 ) ℃(Automatic)
2.3 mV：
Measuring range
-1999mV ~ 0 ~ 1999mV
Resolution
1mV
Accuracy
±0.1% FS
2.4 Other technical parameters:
Data Storage 800 Groups
Storage Content Numberings, measurements, units of measurement and a
temperature values
Power Supply AA Battery (1.5VX2)
Size and Weight Instrument:(65X120X31) mm/180g ,Suitcases:(360X270X76)
mm/1.5Kg
Quality and Safety
Certification ISO9001:2000, CE
IPClass IP57 Dustproof and waterproof

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3Instrument Description
3.1 LCD Display：
①—— Parameter mode
②—— Measuring value
③—— Measured value storage and
display of numbers, symbols
indicate:
M+— Store Measured value
RM - Recall measurement values Icon
④—— Measurement unit
⑤—— Temperature measurement and unit
⑥—— Smiley face; icon indicates stable readings
⑦—— Instrument calibration indicator
⑧—— Low battery reminder
3.2 Operation keys
The meter has 5 operation keys in total
3.2.1 — Switch on / off key
3.2.2 — Calibration key
（a）When in the measurement mode, press this key to enter into calibration mode.
（b）When in the parameter setting mode, press this key to change the number or
ON/OFF state.
3.2.3 — Function key
(a) When in pH measuring mode, short press to change measurment parameters, long press
this key to enter into parameter setting mode P1, P2, P3 ……
(b) When in Conductivity measuring mode, press this key to enter into parameter settings
mode P1, P2, P3 ……
(c) When in Fluoride measuring mode, press this key to enter into parameter setting
mode P1, P2, P3 ……
3.2.4 — Backlight and enter key
(a) When in the measuring mode, short press (< 1.5s ) to turn the backlight display on or off;

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(b) When in the calibration mode or the parameter setting mode, press this key to confirm, and
to make the meter enter into measuring state;
(c) When in pH measuring mode, press this key to change resolution simultaneously:
0.01→0.1 pH
(d) When in Conductivity measuring mode, press this key to change parameter
simultaneously: TDS→SAL→RES→COND.
(e) When in Ion measuring mode, press this key to change parameter mode
simultaneously: mg/L → ppm → pX
3.2.5— The combination key of memory storage and recall memory.
(a) When in the measurement mode, short press this button (< 1.5s) to save the measuring
data. Long press this button(＞2s) to display the stored measuring data.
(b) When in the parameter setting mode, press this button to change the unit % → mol →
g/cm3 → g/L or turn the meter ON/OFF.
3.3 Memory Storage, Recall Memory, and Clear Memory:
3.3.1 Memory Storage
While in the measurement mode, when the measuring data is stable and the smiley face icon
appears, short press key(＜1.5s), LCD will display “ M+ ” icon and a storage serial, and
meanwhile storing all of the measuring information. It can store up to 300 groups.
3.3.2 Display measuring information：
(a) While in the the measurement mode, long press (＞2s), meter will display the last
stored information, and the storage number and “RM” icon will appear in the lower right
corner of the LCD, and the complete measuring information.
Again short press or meter will in turn display all the measuring data, Hold
or to quickly check the measuring data.
(b) In the data displaying mode (there are “ RM ” and storage number in the upper right
corner of the LCD), press key to return to the measuring mode.
3.3.3. Clear the stored measuring information: In the data displaying mode, press the
key for 5 seconds, LCD will appear CLr for 2 seconds. It means that all the storage has been
eliminated and returns to measuring mode.

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4Fluoride concentration measurement
4.1 Preparation
4.1.1 Press key to start connect F501 -fluoride ion electrode; the meter automatically
switches to the fluoride concentration measurement mode.
4.1.2 Hold to change fluoride concentration unit from mg/l, ppm to pX, release the button
after selection.
4.1.3 Activate the electrode in 19.00mg/L calibration solution for about 10-20 minutes (as long as
the smiley face icon stays stably on the screen) before calibration and measurement.
(Please note that the display value during activation is random).
4.2 Calibration
4.2.1 Press , LCD displays " 0.19 mg/L ", and LCD top right corner CAL and the bottom left L
will be flashing, indicating that the meter has entered the 1th point calibration mode and the
calibration solution is 0.19 mg/l; Rinse the fluoride-ion electrode in distilled or deionized
water and shake off the excess water; dip the electrode into 0.19 mg/L calibration solution,
stir gently and let it stand still. When measuring value is stable and icon stays on screen,
then press key again, End and 19.0 mg/L will be displayed after a seconds. While LCD
top right corner CAL and bottom left corner Hflashing, indicating the meter has entered the
2nd calibration mode and the calibration solution is 19.00 mg/L.
4.2.2 Dry the fluoride-ion electrode with clean tissue paper, dip into 19.00 mg/L Calibration
solution, stir gently and let it stand still, when the reading is stabile and stays on screen,
then press after a few seconds End shows up, indicating the end of calibration; LCD
left corner shows two-point calibration icons Land H; The instrument automatically enters
measuring mode.

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4.3 Sample Measuring
4.3.1 Rinse the fluoride-ion electrode in distilled or deionized water and dap off excess water
with clean tissue; soak into solution, stir gently and let it stand still; get the readings
when measuring vaule is stable and stays on screen.
4.3.2 Hold to show Fluoride concentrations in different units, release after selection.
4.3.3 Short press key, the meter enters the mV mode and displays the mV value of the
fluoride ion concentration.
4.4 Parameter Settings
Table (4-3)
Symbol Parameter sets the project
Code
Parameters
P1 Temperature unit selection ℃℉
P2 Backlight display time setting 0-1-3-6 min
P3 Auto power off time setting 0-10-20 min
P4
Restore to factory default
settings
OFF-ON
4.4.1 Temperature units ° c/ºf selection (P1)
Long Press to enter P1，remaining operations see section 5.4.5
4.4.2 Backlight display time setting (P2)
In P1, long press to enter P2，remaining operations see section 5.4.6
4.4.3 Auto-off time setting (P3)
In P2, press to enter P3, remaining operations see section 5.4.7
4.4.4 Restore factory default (P4)
In P3, press to enter P4, remaining operations see section 5.4.8
4.5 Special Notes
4.5.1 The meter does not automatically recognize calibration solutions. Please make sure to use
correct solution according to the displayed reminders "0.19 mg/L " or " 19.00 mg/L ".

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4.5.2 The calibration solution can be easily polluted, especially for low concentration solution
(0.19 mg/l). Please pay attention to avoid contamination otherwise a large measuring error
will occur. Replace the solution after 4~5 times of use.
4.5.3 When test solution in the order from low-concentration to high-concentration, the
electrode does not need to be rinsed, just shake off or dry the excess solutions with clean
tissue. If it’s from high-concentration to low-concentration, you need to rinse the electrode
with distilled or deionized water, otherwise it will affect the accuracy significantly.
4.5.4 Typically the meter needs to calibrated before use. But when requirement of accuracy is
low, calibration is not necessary. Or try the electrode in the calibration solution, if the error
is very small, calibration is not necessary.
4.5.5 According to the theory of Isothermal measurements of ion-selective electrode, the
smaller the difference of temperature between test solution and the calibration solution, the
higher the measuring accuracy is. Typically, temperature difference between test solution and
calibration solution should ≤±15℃; for high accuracy measurement, the temperatures should
be the same.
4.5.6 When test is completed, dry electrode and store with the cap on.
4.5.7 When the meter is functioning abnormally, please set P4 as “ON”to restore the meter to
factory default mode, and then perform calibration and measurements again.
5pH Measurement
5.1 Preparing the Meter
5.1.1. Connect the 201T-S pH Electrode to the meter; loosen the cap of the storage bottle of
electrode; screw off the storage bottle; Press to turn on meter.
5.2 Meter Calibration
5.2.2. Use distilled water to rinse off electrode and then dry it with clean tissue, then soak it
into the pH7.00 buffer solution, stir the electrode gently and let it stand still,
5.2.1. Press to enter calibration mode, LCD displays C1, indicating the first point
of calibration; Wait for a stable reading and to appear and stay, then press

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again, the LCD will show a blinking 7.00 pH, indicating the 1st point of calibration is
completed; a stable pH value and a blinking C2 will be displayed, indicating the first
point calibration has been finished and the meter enters the second point of calibration.
5.2.3. Rinse the pH electrode in distilled water and dry it, then soak it into the pH4.00 buffer
solution, stir the electrode gently and let it stand still, waiting for a stable reading and a
smiley face icon to appear and stay, then again press , the LCD will show a
blinking 4.00 pH, a stable pH value and a blinking C3 will be displayed, indicating the
second-point calibration has been finished and the meter enters the third-point
calibration.
5.2.4. Rinse the pH electrode in distilled water and dry it, then soak
it into the pH 10.01 buffer solution, stir the electrode gently
and let it stand still,, waiting for a stable reading and a smiley
face icon to appear and stay, then again press , the
LCD will show a blinking 10.01 pH. A stable reading and L M
Hcalibration icons will be displayed, see picture (4-1), indicating the three-point
calibration has been finished and the meter automatically returns to measuring mode.
5.2.5. Notes
(a) This meter can perform one-point, two-point or three-point automatic calibrations. After
the first point calibration (see item 5.2.2.), press to confirm one-point calibration
and return to measuring mode. The indication icon Mstanding for one-point calibration
will appear on the lower left corner of LCD. When the requirement of accuracy is
≤±0.1pH, users can perform a one-point calibration with the pH7.00 buffer solution.
(b) After the second-point calibration, (see item 5.2.3.), press to confirm two-point
calibration and return to measuring mode. The indication icon L and M for two-point
calibration will appear on the lower left corner of LCD. User can choose pH4.00 and
pH7.00 to calibrate if the measurement is within the acidity range and choose pH7.00
and pH10.01 to calibrate if within the alkalinity range.
(c) Users should perform a three-point calibration to reach a more accurate measurement if
the measuring range is wide, or if the electrode has been used for long or has aging
phenomenon. If it’s a new electrode, a three-point calibration is necessary to adjust the
meter’s slope to match the pH electrode.

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5.3 Sample Test
Soak the pH electrode into the sample solution after rinsing and drying, hold the
electrode still. Take the readings when the smiley face icon shows up and stays on screen
(indicates a stable reading).
pH isothermal measurement principle
According to the theory of Isothermal measurements, the smaller the difference of the
temperatures between test solution and the calibration solution, the higher the
measuring accuracy is. Typically, temperature difference between test solution and
calibration solution should ≤±15℃; for high accuracy measurement, the temperatures
should be the same.
5.4 Parameter Settings
5.4.1. pH measuring parameter setting (Chart (5-1))
Chart (5-1)
Prompt Parameter Setting Items Code Parameters
P1 pH buffer solution series
selection
SOL USA(U.S.A series)
NIS (NIST series)
CH (China series)
P2 Purified water pH temperature
compensation setting
PU1 OFF-On
P3 Ammonia added purified water
pH temperature compensation
setting
PU2 OFF-On
P4 Temperature unit setting ℃℉
P5 Back light display time setting BL 0-1-3-6min
P6 Auto power off setting AC 0-10-20min
P7 Restore to Factory Default OFF-On
5.4.2. pH buffer solution series selection (P1)
(a) Press key, meter enters P1 mode: see picture (4-2).

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(b) Press or key to choose buffer solution series:
( Europe & U.S.A series) —1.68, 4.00, 7.00,10.01 and 12.45 pH
(NIST series) — 1.68, 4.01, 6.86, 9.18 and 12.45 pH
( (China series) — 1.68, 4.00, 6.86, 9.18 and 12.46 pH
(c) Press key to enter next parameter setting or press key to confirm and
return to measuring mode.
5.4.3. Purified water pH temperature compensation setting (P2)
(a) Short press key in the mode P1, the meter enters mode P2,
see picture (4-3).
(b) Press or to choose ON or OFF.
(c) Press key to enter next parameter setting or press
key to confirm and return to measuring mode.
(d) The default setting is “ OFF ”.
Note: A PU-1 icon will appear in the upper right corner of the LCD if purified water
temperature compensation function is set by the user.
5.4.4. Ammonia added purified water pH temperature compensation
setting (P3)
(a) Short press key in mode P2 to enter mode P3, see picture
(4-4).
(b) Press or key to choose ON or OFF
(c) Press to enter next parameter setting or press key to confirm and return
to measuring mode.
(d) The default setting is “ OFF ”.
Note: A PU-2 icon will appear in the upper right corner of the LCD if purified water
temperature compensation function is set by the user.

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5.4.5. Temperature unit ℃/℉setting (P4)
(a) Short press key in mode P3 to enter mode P4, see
picture (4-5).
(b) Press or key to choose temperature unit:
℃or ℉.
(c) Press key to enter into next parameter setting or press key to confirm and
return to measuring mode.
5.4.6. Backlight display time setting (P5)
(a) Short press key in mode P4 to enter mode P5, see
picture (4-6).
(b) Press or key to choose the time of back light
auto power off: 0 min, 1 min, 3 min or 6 min. The back light
display function will be closed if choosing a 0min.
(c) Press key to enter into next parameter setting or press
key to confirm and return to measuring mode.
(d) The producer setting for P5 is 1min.
5.4.7. Auto power off time setting (P6)
(a) Short press key in mode P5 to enter into mode P6,
see picture (4-7).
(b) Press or key to choose the time: 0min,
10min or 20min. The auto power off function will be closed if choosing 0min.
(c) Press key to enter into next parameter setting or press key to confirm and
return to measuring mode.
(d) The producer setting for P6 is 10min.
5.4.8. Restore to producer setting (P7)
(a) Short press key in mode P6 to enter into mode P7, see
picture (4-8).
(b) Press or key to choose “ ON”, means that all

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the pH measuring parameters have been restored to the factory default setting.
5.5 Special Notes
5.5.1. The frequency that you need to calibrate your meter depends on the tested samples,
performance of electrodes, and the requirement of the accuracy. For high-accuracy
measurements (≤ ±0.02pH), the meter should be calibrated before test every time; For
ordinary-accuracy measurements (≥±0.1pH), once calibrated, the meter can be used for about
a week or longer. In the following cases, the meter must be re-calibrated before testing:
a) The electrode hasn’t been used for a long time or a new electrode is connected.
b) After measuring strong acid (pH<2) or strong base (pH>12) solutions.
c) After measuring fluoride-containing solution and strong organic solution
d) There is a significant difference between the temperature of the test sample and the
temperature of the buffer solution that is used in the last calibration.
5.5.2. The soaking solution contained in the supplied protective bottle is used to maintain
activation in the glass bulb and junction. Loosen the capsule, remove the electrode and rinse
in distilled water before taking a measurement. Insert the electrode and tighten the capsule
after measurements to prevent the solution from leaking. If the soaking solution is turbid or
moldy, replace the KCL solution (Product# AI1107).
5.5.3. For calibration accuracy, the pH of the standard buffer solution must be reliable. The buffer
solution should be refreshed often, especially after heavy use. We recommend 10-15 times of
use before replacing the pH buffers.
5.5.4. Always keep the meter clean and dry; especially around the socket connecting the meter
and electrode, otherwise it may lead to inaccurate measurements or a damaged probe/meter.
To clean, dry them with medical cotton and rubbing alcohol if the connectors appear dirty.
5.5.5. The sensitive glass bulb at the front of the combination electrode should not come in
contact with hard surfaces. Scratches or cracks on the electrode will cause inaccurate
readings. Before and after each measurement, the electrode should be rinsed with distilled
water and dried. If a sample sticks to the electrode or it’s contaminated, the electrode should
be thoroughly cleaned using a soft brush with soap water and then rinsed with distilled water.

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After that, soak it in the KCL solution again for 6 hours.
5.5.6. An electrode be used for a long time, or measured solution which contains a polluting solute
easily for the sensitive bulb, or a substance resulting in jam at the junction, the electrode will
be getting passivated, its sensitivity will decrease and its response is getting slow, the reading
are not correct. Users could adopt the following methods to clean in various cases:
(a) Electrodes that have been used over a long period of time will become aged. Submerge the
electrode in 0.1mol/L hydrochloric acid for 24 hours, then rinse the electrode in distilled
water, then submerge it in 3M KCL soaking solution for 24 hours.
(b) The method to prepare 0.1mol/L hydrochloric acid: dilute 9mL hydrochloric acid in distilled or
deionized water to 1000mL. For serious passivation, submerge the bulb in 4% HF
(hydrofluoricacid) for 3-5 seconds, and rinse it in distilled water, then submerge it in the 3M
KCL soaking solution for 24 hours to renew it.
Clean contaminated glass bulb and junction (please refer to Table-8)
Table-8 Clean contaminated glass bulb and junction
Contamination Cleaning Solutions
Inorganic metal oxide Dilute acid less than 1mol/L
Organic lipid Dilute detergent (weak alkaline)
Resin macromolecule Dilute alcohol, acetone, ether
Proteinic haematocyte sediment Acidic enzymatic solution (saccharated yeast tablets)
Paints Dilute bleacher, peroxide

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5.5.9. The lifespan period for the 201T-S pH Electrode is about 1-1.5 year, but its life will be
shortened if the meter is used incorrectly or is not well maintained. be sure to replace the
electrode once it has aged or tested inaccurately
5.5.10. When an abnormal reading appears during calibration or measurement, please set P7 to
“ON”to restore the meter to Factory Default settings, then re-calibrate the meter before
measurement.
5.6 Self-diagnose Information
When using the meter, the following icons might appear. This is the meter’s self-diagnose
information, which helps users identify problems occurring with the meter or the electrode
when using:
5.6.1. The stable icon of -2.00 pH or 19.99 pH — this icon appears when the value has surpassed
the measuring range. There will also appear such signs when the electrode is not well
connected with the meter or when the electrode is not immerged into the solution. This
is a normal phenomenon.
5.6.2. “Err1”— Abnormal electrode zero potential (<-60mV or >60mV)
5.6.3. “Err2”— Abnormal electrode slope (< 85% or >105%)
When “Err1”or “Err2” appears, the meter can not work properly, please take the
following steps to check and fix the problem:
(a) Check if the electrode bulb has air bubble, if has, please shake the electrode with
force for a few times to eliminate the air bubble inside the sensor.
(b) Check the quality of buffer solution, if it is expired or contaminated. If so, please
replace with new ones.
(c) Set the meter to factory default mode then recalibrate it.
If the meter still cannot recover to the normal state after doing the above steps,
please replace a new pH electrode.

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6mV Measurement
6.1 Sample Test
6.1.1. Press key to turn on, and short press to switch to mV mode;
6.1.2. Connect the ORP probe (Product# AI1315, sold separately), soak it into sample solution,
stir gently and let it stand still. Get the readings when the smiley face ion appears and
stay on the screen.
7Complete Kit
WS100 Fluoride/pH meter
201T-S 3-in-1 plastic pH/ATC electrode
F501 Fluoride combination electrode
pH standard buffer solution (pH4.00, pH7.00and pH10.01, 50mL)
Fluoride calibration solution (0.19ml/L and 19mg/L, 50mL)
Screw driver
3x Spare AA batteries
Operation manual
Carrying case
8Warranty
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 (Europe) GmbH, any
malfunctioned or damaged product attributable to responsibility of APERA INSTRUMENTS (Europe)
GmbH for a period of two years from the delivery (a six-month limited warranty applies to probes).
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), accidental
damage, 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 tester or
probe.

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9Appendix 1. Fluoride Concentration Conversion Table
APERA INSTRUMENTS (Europe) GmbH
Wilhelm-Muthmann-Straße 18
42329 Wuppertal, Germany
Tel. [phone]
Email: [e-mail]
mol/L
pF
mg/L
ppm
1 ×10-3
3.00
19.00
19.00
1 ×10-4
4.00
1.90
1.90
1 ×10-5
5.00
0.19
0.19