Hanna Instruments HI 8043 User manual

HI8043
Portable Dissolved Oxygen
Meter
INSTRUCTION MANUAL

Thank you for choosing a Hanna Instruments product.
Please read this instruction manual carefully before
using the instrument.
This manual will provide you with the necessary
information for correct use of the instrument, as well
as a precise idea of its versatility.
If you need additional technical information, do not
hesitate to e‑mail us at [email protected] or view
our worldwide contact list at www.hannainst.com.
Dear
Customer,
All rights are reserved. Reproduction in whole or in part is prohibited
without the written consent of the copyright owner, Hanna Instru-
ments Inc., Woonsocket, Rhode Island, 02895, USA.

3
Included .............................................................................
Safety measures..................................................................
Description..........................................................................
Product diagram..................................................................
Probe diagram ....................................................................
Probe preparation................................................................
Specifications......................................................................
Probe polarization ...............................................................
Calibration..........................................................................
Operational guide................................................................
Probe and membrane maintenance.......................................
Battery replacement.............................................................
Accessories..........................................................................
TABLE OF CONTENTS
4
4
6
8
10
18
21
5
7
9
11
19
22

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Remove the instrument and accessories from the packaging
and verify damage has not occurred during shipping. Remove
protective film from meter. Notify your nearest Hanna Customer
Service Center if damage is observed.
Packaging for each HI8043 instrument includes:
• Spare membrane with O‑Ring (2 pcs.)
• Calibration screwdriver
• 9V battery
• Instruction Manual
• Quality Certificate
• HI76401: Dissolved Oxygen probe
• HI7041S: electrolyte solution (30 mL)
• Protective cap
Note: Save all packing material until you are sure that the
instrument works correctly. Any defective item must be
returned in its original packing.
INCLUDED
Before using this product, make sure that it is entirely suitable
for your specific application and for the environment in which
it is used.
Operation of this instrument may cause interference to other
electronic equipment, requiring the operator to take steps to
correct interference. Any variation introduced by the user to
the supplied equipment may degrade the instrument’s EMC
performance.
To avoid damages or burns, do not put the instrument in
microwave ovens. For your and the instrument’s safety, do not
use or store the instrument in hazardous environments.
SAFETY MEASURES

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HI8043 is a portable meter for Dissolved Oxygen measurements.
It is housed in a lightweight case, with an easy‑to‑read LCD.
Dissolved oxygen and temperature measurements can be
performed in the field (wastewater treatment, fish‑farming, water
analysis, etc.) as well as in the laboratory without compromising
accuracy.
Dissolved oxygen is indicated in mg/L (ppm) and the reading is
compensated for the temperature effect (ATC).
The dissolved oxygen probe is provided with a membrane for
covering the polarographic sensors, and features a built‑in
thermistor for temperature measurements and compensation.
The thin permeable membrane isolates the sensor elements from
the sample, but allows oxygen to enter.
A voltage is applied across the sensor, and the oxygen that has
passed through the membrane reacts causing the current to flow,
hence determining a reading.
A convenient feature of the instrument is its standby mode which
keeps the probe polarized and ready for instant measurements.
DESCRIPTION

6
PRODUCT DIAGRAM
1. Liquid Crystal Display (LCD)
2. stb (to switch the meter on and polarize the probe. Use
this standby position with out switching the meter off if
you are going to take further measurements.)
3. off (to switch the meter off)
4. Rotary switch
5. Zero calibration trimmer
6. Slope calibration trimmer
7. °C calibration trimmer
8. O2measurement
9. °C measurement
10. Probe connector
1
2
3
4
5
6
7
8
9
10

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PROBE DIAGRAM
1
2
3
6
7
8
9
4
5
1. Watertight Shielded Cable
2. Probe Body
3. O‑Ring Seal
4. Protective Cap
5. DO Probe
6. Silver Chloride Anode
7. Platinum Cathode (sensor)
8. Oxygen Permeable Membrane
9. Membrane Cap
HI76401
Dissolved Oxygen Probe

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The main operating modes of HI8043 are calibration and
measurement. Follow this general outline of steps to get you
started.
1. Decide how the meter will be used and set up a clean area.
2. Connect the HI76401 probe to the meter.
3. Turn HI8043 on using the rotary switch.
4. Calibrate the probe.
You are now ready for measurements.
All DO probes are shipped dry. To hydrate the probe and prepare
it for use, connect it to the meter and proceed as follows.
1. Remove the red & black plastic cap. This cap is only
used for protecting the probe during shipment, and
can be thrown away.
2. Wet the sensor by soaking the bottom
(2.5 cm/1”) of the probe in HI7041S
electrolyte solution for 5 minutes.
3. Rinse the supplied membrane with some
electrolyte while shaking it gently. Refill
with clean electrolyte.
4. Gently tap the sides of the membrane with
your finger tip to ensure that no air bubbles
remain trapped inside. To avoid damaging
the membrane, do not tap the membrane
directly on the bottom.
5. Make sure that the rubber O‑Ring sits properly
inside the membrane cap.
PROBE PREPARATION
6. With the sensor facing down, screw the cap clockwise.
Some electrolyte will overflow. When the probe is not used,
protect the membrane with the supplied cap.

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O2Temperature
Range 0.00 to 19.99 mg/L 0.0 to 50.0 ºC ;
(32.0 to 122.0 °F)
Resolution 0.01 mg/L 0.1 ºC
Accuracy
@ 25 °C / 77 °F
±1.5% F.S. ±0.5 ºC
Calibration Manual, two point (zero and slope)
Temperature
compensation Automatic 0 to 30 ºC (32 to 86 ºF)
Probe
HI76401 polarographic probe with 3 m (10’)
cable (included)
Battery Type 9V alkaline (1 pcs.)
Battery Life Approximately 100 hours of continuous use
Environment 0 to 50 ºC (32 to 122 ºF)
Max 95% RH non‑condensing
Dimensions 180 x 83 x 40 mm (7.1 x 3.3 z 1.6”)
Weight 240 g (8.4 oz.)
SPECIFICATIONS

10
PROBE POLARIZATION
When the probe is under polarization it is continuously fed with a
voltage of approximately 800 mV.
Probe polarization is essential for stable measurements to be
taken with the same degree of accuracy.
With polarized probe, oxygen is continually “consumed” by
passing through the sensitive diaphragm and dissolving in the
electrolyte solution contained in the probe.
If this operation is interrupted, the electrolyte solution continues
to be enriched with oxygen until it reaches an equilibrium with
the surrounding solution.
If measurements are taken with a
non‑polarized probe, the oxygen level
detected by the meter is the sum of the
oxygen dissolved in the tested sample
and that of the electrolyte solution itself.
By leaving the instrument in the “stb” mode (i.e. keeping
the probe in a continual state of polarization), the oxygen of
the electrolyte solution is progressively “consumed”, and the
following measurements detect only the quantity of oxygen
dissolved in the sample to be tested.
Therefore, in order to keep the probe continuously polarized it is
necessary to switch the meter to the “stb” mode and wait for at
least 30 minutes. This should be done with the probe covered
with the protective cap and filled with some electrolyte solution.
Polarization is not maintained when the instrument is switched
"off".

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Calibration should be made:
• after approximately 20 hours of use
• whenever the electrolyte or membrane is changed and after
cleaning the electrode
• after use in aggressive solutions.
Accessories:
• 200 mL of HI7040 solution
• 1 bottle of HI7041S solution
Calibration at sea level:
• Set the knob to the “stb” position
and wait 30 minutes for a complete
polarization of the probe.
Zero Calibration
• Switch from “stb” to “O2” position.
• Remove the membrane protective
cap, immerse the probe in HI7040
zero oxygen solution and wait for
approximately 5 minutes.
• The indications given by the instrument
must fall to stabilization levels. If
the probe has not been sufficiently
polarized, the readout will continue
to fluctuate. In this case, switch back
to “stb” position, place the protective
cap and wait for a few hours for complete polarization before
proceeding.
• Using a small screwdriver, turn the “Zero” calibration trimmer
until the display reads zero.
CALIBRATION

12
Slope Calibration
In order to perform a highly accurate calibration,
take a B.O.D. bottle and fill with water to a depth
of 1‑2 cm (½ ‑ ¾”). Seal the bottle with the probe
inside.
If this calibration is carried out with the
bottle opened to air rather than according
to the conditions described above, the
margin of error is approximately 0.1 ppm.
• Switch the instrument to “°C”, wait for
reading to stabilize and note the temperature of the water.
• See Table on page 12 for the DO
reading corresponding at the noted
temperature.
• Switch to “O2” position and adjust
the “Slope” trimmer until the correct
reading is displayed.
E.g. at 20.5°C the trimmer should be adjusted to read 9.08.
If you cannot get zero reading, the probe is probably defective.
Check the membrane, electrode and electrolyte solution.
After the zero calibration has been completed, rinse the probe
thoroughly with tap water.
CALIBRATION

13
CALIBRATION
Altitude Compensation
If the calibration is not performed at sea level, a correction should
be made for the altitude effect according to Table on page 13.
E.g. at 20.5°C and at an altitude of 300 m above sea level, the
“Slope” trimmer should be adjusted to read 9.08 x 0.96 = 8.72.
Salinity Compensation
An additional correction has to be performed if the sample
presents significant salinity concentrations.
In such case, the reading has to be adjusted according to Table
on page 14. E.g. at 20.5°C and if the sample has a salinity
content of 3 g/L, the “Slope” trimmer should be adjusted to read
9.08 ‑ (3 x 0.0478) = 8.94.

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°C 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
0 14.62 14.58 14.54 14.50 14.46 14.42 14.38 14.34 14.30 14.26
1 14.22 14.18 14.14 14.10 14.06 14.02 13.98 13.94 13.91 13.87
2 13.83 13.79 13.76 13.72 13.68 13.64 13.61 13.57 13.54 13.50
3 13.46 13.43 13.39 13.35 13.32 13.28 13.25 13.21 13.18 13.14
4 13.11 13.07 13.04 13.01 12.97 12.94 12.91 12.87 12.84 12.81
5 12.77 12.74 12.71 12.67 12.64 12.61 12.58 12.54 12.51 12.48
6 12.45 12.42 12.39 12.36 12.32 12.29 12.26 12.23 12.20 12.17
7 12.14 12.11 12.08 12.05 12.02 11.99 11.96 11.93 11.90 11.87
8 11.84 11.81 11.79 11.76 11.73 11.70 11.67 11.64 11.62 11.59
9 11.56 11.53 11.51 11.48 11.45 11.42 11.40 11.37 11.34 11.32
10 11.29 11.26 11.24 11.21 11.18 11.16 11.13 11.10 11.08 11.05
11 11.03 11.00 10.98 10.95 10.93 10.90 10.88 10.85 10.83 10.80
12 10.78 10.75 10.73 10.70 10.68 10.66 10.63 10.61 10.58 10.56
13 10.54 10.51 10.49 10.47 10.44 10.42 10.40 10.37 10.35 10.33
14 10.31 10.28 10.26 10.24 10.22 10.19 10.17 10.15 10.13 10.11
15 10.08 10.06 10.04 10.02 10.00 9.98 9.96 9.93 9.91 9.89
16 9.87 9.85 9.83 9.81 9.79 9.77 9.75 9.73 9.71 9.69
17 9.67 9.64 9.63 9.60 9.59 9.57 9.55 9.53 9.51 9.49
18 9.47 9.45 9.43 9.41 9.39 9.37 9.35 9.33 9.31 9.30
19 9.28 9.26 9.24 9.22 9.20 9.18 9.17 9.15 9.13 9.11
20 9.09 9.08 9.06 9.04 9.02 9.00 8.99 8.97 8.95 8.93
21 8.92 8.90 8.88 8.86 8.85 8.83 8.81 8.80 8.78 8.76
22 8.74 8.73 8.71 8.69 8.68 8.66 8.64 8.63 8.61 8.60
23 8.58 8.56 8.55 8.53 8.51 8.50 8.48 8.47 8.45 8.43
24 8.42 8.40 8.39 8.37 8.36 8.34 8.33 8.31 8.29 8.28
25 8.26 8.25 8.23 8.22 8.20 8.19 8.17 8.16 8.14 8.13
26 8.11 8.10 8.08 8.07 8.06 8.04 8.03 8.01 8.00 7.98
27 7.97 7.95 7.94 7.93 7.91 7.90 7.88 7.87 7.68 7.84
28 7.83 7.81 7.80 7.79 7.77 7.76 7.75 7.73 7.72 7.71
29 7.69 7.68 7.67 7.65 7.64 7.62 7.61 7.60 7.59 7.57
30 7.56 7.55 7.53 7.52 7.51 7.49 7.48 7.47 7.46 7.44
31 7.43 7.42 7.41 7.39 7.38 7.37 7.35 7.34 7.33 7.32
32 7.31 7.29 7.28 7.27 7.26 7.24 7.23 7.22 7.21 7.20
33 7.18 7.17 7.16 7.15 7.14 7.12 7.11 7.10 7.09 7.08
34 7.07 7.05 7.04 7.03 7.02 7.01 7.00 6.98 6.97 6.96
35 6.95 6.94 6.93 6.92 6.90 6.89 6.88 6.87 6.86 6.85
36 6.84 6.83 6.81 6.80 6.79 6.78 6.77 6.76 6.75 6.74
37 6.73 6.72 6.71 6.70 6.68 6.67 6.66 6.65 6.64 6.63
38 6.62 6.61 6.60 6.59 6.58 6.57 6.56 6.55 6.54 6.53
39 6.52 6.51 6.49 6.48 6.47 6.46 6.45 6.44 6.43 6.42
40 6.41 6.40 6.39 6.38 6.37 6.36 6.35 6.34 6.33 6.32
41 6.31 6.30 6.29 6.28 6.27 6.26 6.25 6.24 6.23 6.22
42 6.21 6.21 6.20 6.19 6.18 6.18 6.16 6.15 6.14 6.13
43 6.12 6.11 6.10 6.09 6.08 6.07 6.06 6.05 6.04 6.03
44 6.02 6.02 6.01 6.00 5.99 5.98 5.97 5.96 5.95 5.94
45 5.93 5.92 5.91 5.91 5.90 5.89 5.88 5.87 5.86 5.85
46 5.84 5.83 5.82 5.82 5.81 5.80 5.79 5.78 5.77 5.76
47 5.75 5.74 5.73 5.73 5.72 5.71 5.70 5.69 5.68 5.67
48 5.67 5.66 5.65 5.64 5.63 5.62 5.61 5.60 5.60 5.59
49 5.58 5.57 5.56 5.55 5.55 5.54 5.53 5.52 5.51 5.50
50 5.49
Dissolved Oxygen (ppm) in Fresh Water as a function of Temperature (°C)
CALIBRATION

15
Altitude
(Meters)
Atmospheric Pressure
KPa
Correction
Factor
Sea level 101.3 1.00
50 100.7 0.99
100 100.1 0.99
150 99.4 0.98
200 98.8 0.98
300 97.6 0.96
400 96.4 0.95
500 95.2 0.94
600 94.0 0.93
700 92.8 0.92
800 91.7 0.90
900 90.5 0.89
1000 89.4 0.88
1100 88.3 0.87
1200 87.2 0.86
1300 86.1 0.85
1400 85.0 0.84
1500 84.0 0.83
1600 82.9 0.82
1700 81.9 0.81
1800 80.9 0.80
1900 79.9 0.79
Correction for measurements at different altitude
CALIBRATION

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°C
Quantity to be
subtracted per mg/L
of NaCl
°C
Quantity to be
subtracted per mg/L
of NaCl
0 0.0892 26 0.0410
1 0.0861 27 0.0400
2 0.0830 28 0.0391
3 0.0802 29 0.0382
4 0.0779 30 0.0373
5 0.0749 31 0.0364
6 0.0724 32 0.0356
7 0.0701 33 0.0348
8 0.0678 34 0.0341
9 0.0657 35 0.0333
10 0.0637 36 0.0326
11 0.0618 37 0.0319
12 0.0599 38 0.0312
13 0.0582 39 0.0306
14 0.0565 40 0.0299
15 0.0549 41 0.0293
16 0.0533 42 0.0287
17 0.0519 43 0.0281
18 0.0505 44 0.0275
19 0.0491 45 0.0270
20 0.0478 46 0.0265
21 0.0466 47 0.0259
22 0.0454 48 0.0254
23 0.0442 49 0.0249
24 0.0431 50 0.0244
25 0.0421
Correction for salinity effect
CALIBRATION

17
Temperature Calibration
The temperature scale should be calibrated at least every
3 months or whenever the readings are in doubt.
• Immerse the bottom 60 mm (2.4”) of the
probe in a beaker containing water.
• Switch the knob to the “°C” position
and agitate the water for at least
10 minutes to reach the thermal
equilibrium between the probe and
water.
• Using a HI98501 or another thermometer
with a resolution of 0.1°C, check the
temperature of the water (e.g. 20.0°C).
• Adjust the “°C” trimmer until the display
shows the noted temperature.
Note: It is important to ensure the thermal equilibrium
between probe and water, because 1 degree of
temperature difference entails an error of ±3% in dissolved
oxygen measurement.
CALIBRATION

18
Make sure the meter has been calibrated and the protective cap
has been removed.
Immerse the tip of the probe in the sample to be tested.
For accurate dissolved oxygen measurements a water movement
of at least 0.3 m/sec is required.
This movement will ensure that the oxygen depleted membrane
surface is constantly replenished. A moving stream will provide
adequate circulation.
To quickly check if the water speed is sufficient, wait for stable
reading and then move the DO probe. If the reading remains
stable, measurement conditions are correct. If the reading
increases, the water movement is too low.
During field measurements, this condition may be met by
manually agitating the probe. Accurate readings are not possible
while the liquid is at rest.
During laboratory measurements, the use of a magnetic stirrer is
recommended. In this way errors due to the diffusion of ambient
oxygen in the solution are minimized.
Anyway, the time necessary for reaching the thermal equilibrium
between probe and sample must be allowed (a few minutes for a
temperature difference of several degrees).
OPERATIONAL GUIDE

19
The DO probe body is made of reinforced
plastic for maximum durability. A thermistor
temperature sensor provides temperature
measurements and compensation. When
not in use, it is always recommended to
protect the probe against damage and dirt
with the supplied cap.
To replace the membrane or refill it with electrolyte, proceed as
follows:
• Remove the protective cap by gently
twisting and pulling it as shown in figure 1.
• Unscrew the membrane by turning it
counterclockwise (see fig.2)
• Wet the sensor by soaking the bottom
(2.5 cm / 1”) of the probe in HI7041S
electrolyte solution for 5 minutes.
• Rinse the new membrane supplied with the
meter) with some electrolyte while shaking
gently. Refill with clean electrolyte.
• Gently tap the sides of the membrane with
your finger to ensure that no air bubbles
remain trapped inside. Do no directly
tap the bottom as this will damage the
membrane.
• Make sure that the rubber O‑Ring is seated properly inside the
membrane cap.
• With the sensor facing down, screw the membrane cap
clockwise. Some electrolyte will overflow.
PROBE AND MEMBRANE MAINTENANCE

20
The Platinum cathode (7 in the Probe diagram at page 7) should
always be bright and untarnished. If it is tarnished or stained,
which could be due to contact with certain gases or extended
use with a loose or damaged membrane, the cathode should be
cleaned. Use a lint‑free cardboard or cloth and rub the cathode
very gently side to side 4‑5 times.
This will be enough to polish and remove any stains without
damaging the platinum tip. Afterwards, rinse the probe with
deionized or distilled water and install a new membrane cap
using fresh electrolyte. Recalibrate the instrument.
Important: in order to have accurate and stable measurements,
it is important that the surface of the membrane to be in perfect
condition. This semi‑permeable membrane isolates the sensor
elements from the environment but allows oxygen to enter. If any
dirt is observed on the membrane, rinse carefully with distilled or
deionized water. If any imperfection still exists, or any damage
is evident (such as wrinkles or tears), the membrane should be
replaced. Make sure that the O‑Ring is properly seated in the
membrane cap.
PROBE AND MEMBRANE MAINTENANCE