Hanna Instruments HI 8043 User manual

1
Instruction Manual
HI 8043
Portable
Dissolved Oxygen Meter
ins
rum ns
OFF O
2
STB
°C
DO meter
HI 8043
ZERO SLOPE °C

3
2
PRELIMINARY EXAMINATION
Remove the instrument from the packing ma-
terial and examine it to make sure that no
damage has occurred during shipping. If there
is any damage, notify your Dealer.
Each meter is supplied complete with:
• HI 76401 DO probe
•Spare membrane with O-ring (2 pcs)
•Protective cap
• HI 7041S electrolyte solution (30 mL)
•Calibration screwdriver
•9V battery (1 pc)
•Instructions
Note: Save all packing material until you are
sure that the instrument functions
correctly. All defective items must be
returned in the original packaging with
the supplied accessories.
GENERAL DESCRIPTION
HI 8043 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 measure-
ments can be performed in the field (waste-
water 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 tem-
perature 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 compensa-
tion.
DearCustomer,
Thank you for choosing a Hanna Instruments
Product.
Please read this instruction manual carefully
beforeusingtheinstrument.
Thismanualwillprovideyouwithalltheneces-
sary information for the correct use of the
instrument.
If you need additional technical information,
do not hesitate to e-mail us at
[email protected]
This instrument is in compliance with the CE
directives.
TABLE OF CONTENTS
Preliminary Examination............................. 3
General Description .................................... 3
Functional Description (Probe) ................... 4
Functional Description (Meter).................... 5
Specifications ............................................. 6
Probe Initial Preparation ............................. 7
Dissolved Oxygen Calibration ..................... 9
Temperature Calibration ............................ 15
Taking Measurements .............................. 16
Probe & Membrane Maintenance ............. 17
Battery Replacement ................................ 19
Accessories.............................................. 20
Warranty ................................................... 21
CE Declaration of Confirmity .................... 22

5
4
FUNCTIONAL DESCRIPTION (METER)
1. Liquid Crystal Display
2. "OFF" (to switch the meter off)
3. "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)
4. "°C" Measurement
5. "O2" Measurement
6. ZERO Calibration Trimmer
7. SLOPE Calibration Trimmer
8. °C Calibration Trimmer
9. Rotary Switch
ins rum ns
OFF O
2
STB °C
DO meter
HI 8043
ZERO SLOPE °C
1
42
9
3
5
6
7
8
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 mem-
brane reacts causing the current to flow, hence
determining a reading.
A convenient feature of the instrument is its
standbymodewhichkeepstheprobepolarized
andreadyforinstantmeasurements.
FUNCTIONAL DESCRIPTION (PROBE)
1. D.O. Probe
2. Protective Cap
3. Watertight Shielded Cable
4. Probe Body
5. O-Ring Seal
6. Silver Chloride Anode
7. Platinum Cathode (sensor)
8. Oxygen Permeable Membrane
9. Membrane Cap

7
6
PROBE INITIAL PREPARATION
PROBE PREPARATION
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 HI 7041S elec-
trolyte solution for 5 minutes.
3. Rinse the supllied membrane (HI 76407A)
with some electrolyte while shaking it gen-
tly. Refill with clean electrolyte.
4. Gently tap the sides of the
membrane with your finger
tip to ensure that no air
bubbles remain trapped in-
side. 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.
6. With the sensor facing
down, screw the cap clock-
wise. Some electrolyte will
overflow.
When the probe is not used,
protect the membrane with the
supplied cap.
Shipping
cap
black
red
SPECIFICATIONS
Range 0.00 to 19.99 mg/L O2
0.0 to 50.0°C (32 to 122 °F)
Resolution 0.01 mg/L O2
0.1°C
Accuracy ±1.5% F.S. (O2)
±0.5°C
Typical EMC ±1.5% F.S. (O2)
Deviation ±1°C
Calibration Manual, 2 point (zero and slope)
Temperature Automatic, 0 to 30°C
Compensation (32 to 86°F)
Probe HI 76401 polarographic
with 3 m (10') cable (included)
Battery Type 1 x 9V
Life approx. 100 hours of continuous use
Environment 0 to 50°C (32 to 122°F); RH max 95%
Dimensions 180 x 83 x 40 mm (7.1 x 3.3 x 1.6")
Weight 240 g (8.4 oz.)

9
8
DISSOLVED OXYGEN CALIBRATION
The calibration should be verified:
• 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 cc of HI 7040 solution
• 1 bottle of HI 7041 solution
Calibration at sea level:
• Switch the meter ON, set
the knob to the "STB"
position and wait 30 min-
utes for a complete polar-
ization of the probe.
ZERO CALIBRATION
• Switch from "STB" to "O2"
position.
• Remove the membrane
protective cap, immerse
the probe in HI 7040 zero
oxygen solution and wait
for approx. 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 be-
fore proceeding.
OFF O
2
STB °C
OFF O
2
STB °C
PROBE POLARIZATION
When the probe is under polarization it is
continuously fed with a voltage of approxi-
mately 800 mV.
Probe polarization is essential for stable mea-
surements 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 oxy-
gen until it reaches an equilibrium with the
surrounding solution.
If measurements are taken with a non-polar-
ized 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. keep-
ing the probe in a continual
state of polarization), the oxy-
gen of the electrolyte solu-
tion is progressively "con-
sumed", and the following measurements de-
tect only the quantity of oxygen dissolved in
the sample to be tested.
Therefore, in order to keep the probe continu-
ously 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.
OFF O
2
STB °C
OFF O
2
STB °C
OFF O
2
STB °C

11
10
E.g. at 20.5°C the trimmer should be ad-
justed to read 9.08.
ALTITUDE COMPENSATION
If the calibration is not performed at sea level,
a correction should be made for the altitude
effect according to Table 2 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 con-
centrations. In such case, the reading has to
be adjusted according to Table 3 on page 14.
E.g. at 20.5°C and if the sample has a salin-
ity content of 3 g/L, the "Slope" trimmer
should be adjusted to read 9.08 - (3 x 0.0478)
= 8.94.
OFF O
2
STB °C
• Using a small screwdriver, turn the "Zero"
calibration trimmer until the display reads
zero.
• If the zero point is
passed, "1" will appear
on the display.
If you cannot get zero reading, the probe
is probably defective. Check the mem-
brane, electrode and electrolyte solution.
After the zero calibration has been completed,
rinse the probe thoroughly with tap water.
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 1 on page 12
for the DO reading corre-
sponding at the noted
temperature.
• Switch to "O2" position
and adjust the "Slope"
trimmer until the correct
reading is displayed.
OFF O
2
STB °C
SLOPE
ZERO °C
SLOPE
ZERO °C
SLOPE
ZERO °C
SLOPE
ZERO °C

13
12
Table 2
Correction for measurements
at different altitude
Table 1
Dissolved Oxygen (ppm) in Fresh Water
as a function of Temperature (°C)
°C
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
ALTITUDE
(METERS)
Sea level
50
100
150
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
CORRECTION
FACTOR
1.00
0.99
0.99
0.98
0.98
0.96
0.95
0.94
0.93
0.92
0.90
0.89
0.88
0.87
0.86
0.85
0.84
0.83
0.82
0.81
0.80
0.79
ATMOSPHERIC
PRESSURE
KPa
101.3
100.7
100.1
99.4
98.8
97.6
96.4
95.2
94.0
92.8
91.7
90.5
89.4
88.3
87.2
86.1
85.0
84.0
82.9
81.9
80.9
79.9
0.5
14.43
14.03
13.66
13.31
12.97
12.64
12.33
12.02
11.73
11.46
11.21
10.96
10.72
10.49
10.26
10.05
9.84
9.64
9.44
9.26
9.08
8.91
8.76
8.61
8.46
8.30
8.15
8.00
7.85
7.70
7.57
7.45
7.35
7.25
7.15
7.05
6.95
6.85
6.75
6.65
6.55
6.45
6.35
6.25
6.15
6.05
5.95
5.85
5.75
5.65
5.55
0.0
14.62
14.23
13.84
13.48
13.13
12.80
12.48
12.17
11.87
11.59
11.33
11.08
10.83
10.60
10.37
10.15
9.95
9.74
9.54
9.35
9.17
8.99
8.83
8.68
8.53
8.38
8.22
8.07
7.92
7.77
7.63
7.50
7.40
7.30
7.20
7.10
7.00
6.90
6.80
6.70
6.60
6.50
6.40
6.30
6.20
6.10
6.00
5.90
5.80
5.70
5.60
0.1
14.58
14.19
13.80
13.45
13.10
12.77
12.45
12.14
11.84
11.56
11.31
11.06
10.81
10.58
10.35
10.13
9.93
9.72
9.52
9.33
9.15
8.97
8.82
8.67
8.52
8.36
8.21
8.06
7.91
7.76
7.62
7.49
7.39
7.29
7.19
7.09
6.99
6.89
6.79
6.69
6.59
6.49
6.39
6.29
6.19
6.09
5.99
5.89
5.79
5.69
5.59
0.2
14.54
14.15
13.77
13.41
13.06
12.74
12.42
12.11
11.81
11.54
11.28
11.03
10.78
10.55
10.33
10.11
9.91
9.70
9.50
9.31
9.13
8.96
8.80
8.65
8.50
8.35
8.19
8.04
7.89
7.74
7.60
7.48
7.38
7.28
7.18
7.08
6.98
6.88
6.78
6.68
6.58
6.48
6.38
6.28
6.18
6.08
5.98
5.88
5.78
5.68
5.58
0.3
14.50
14.11
13.73
13.38
13.03
12.70
12.39
12.08
11.79
11.51
11.26
11.01
10.76
10.53
10.30
10.09
9.89
9.68
9.48
9.30
9.12
8.94
8.79
8.64
8.49
8.33
8.18
8.03
7.88
7.73
7.59
7.47
7.37
7.27
7.17
7.07
6.97
6.87
6.77
6.67
6.57
6.47
6.37
6.27
6.17
6.07
5.97
5.87
5.77
5.67
5.57
0.4
14.46
14.07
13.70
13.34
13.00
12.67
12.36
12.05
11.76
11.49
11.23
10.98
10.74
10.51
10.28
10.07
9.87
9.66
9.46
9.28
9.10
8.93
8.77
8.62
8.47
8.32
8.16
8.01
7.86
7.71
7.58
7.46
7.36
7.26
7.16
7.06
6.96
6.86
6.76
6.66
6.56
6.46
6.36
6.26
6.16
6.06
5.96
5.86
5.76
5.66
5.56
0.6
14.39
14.00
13.62
13.27
12.93
12.61
12.29
11.99
11.70
11.43
11.18
10.93
10.69
10.46
10.24
10.03
9.82
9.62
9.43
9.24
9.06
8.89
8.74
8.59
8.44
8.28
8.13
7.98
7.83
7.69
7.55
7.44
7.34
7.24
7.14
7.04
6.94
6.84
6.74
6.64
6.54
6.44
6.34
6.24
6.14
6.04
5.94
5.84
5.74
5.64
5.54
0.7
14.35
13.96
13.59
13.24
12.90
12.58
12.26
11.96
11.67
11.41
11.16
10.91
10.67
10.44
10.22
10.01
9.80
9.60
9.41
9.22
9.04
8.88
8.73
8.53
8.53
8.27
8.12
7.97
7.82
7.67
7.54
7.43
7.33
7.23
7.13
7.03
6.93
6.83
6.73
6.63
6.53
6.43
6.33
6.23
6.13
6.03
5.93
5.83
5.73
5.63
5.53
0.8
14.31
13.92
13.55
13.20
12.87
12.54
12.23
11.93
11.65
11.38
11.13
10.89
10.65
10.42
10.19
9.99
9.78
9.58
9.39
9.21
9.03
8.86
8.71
8.56
8.41
8.25
8.10
7.95
7.80
7.66
7.53
7.42
7.32
7.22
7.12
7.02
6.92
6.82
6.72
6.62
6.52
6.42
6.32
6.22
6.12
6.02
5.92
5.82
5.72
5.62
5.52
0.9
14.27
13.88
13.52
13.17
12.83
12.51
12.20
11.90
11.62
11.36
11.11
10.85
10.62
10.39
10.17
9.97
9.76
9.56
9.37
9.19
9.01
8.85
8.70
8.55
8.40
8.24
8.09
7.94
7.79
7.64
7.51
7.41
7.31
7.21
7.11
7.01
6.91
6.81
6.71
6.61
6.51
6.41
6.31
6.21
6.11
6.01
5.91
5.81
5.71
5.61
5.51

15
14
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 wa-
ter.
• Switch the knob to the
"°C" position and agitate
the water for at least 10
minutes to reach the ther-
mal equilibrium between the
probe and water.
• Using a ChecktempC 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.
TEMPERATURE CALIBRATION
OFF O
2
STB °C
°C
Table 3
Correction for salinity effect
°C
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Quantity to be
subtracted per mg/l
of NaCl
0.0892
0.0861
0.0830
0.0802
0.0779
0.0749
0.0724
0.0701
0.0678
0.0657
0.0637
0.0618
0.0599
0.0582
0.0565
0.0549
0.0533
0.0519
0.0505
0.0491
0.0478
0.0466
0.0454
0.0442
0.0431
0.0421
Quantity to be
subtracted per mg/l of
NaCl
0.0410
0.0400
0.0391
0.0382
0.0373
0.0364
0.0356
0.0348
0.0341
0.0333
0.0326
0.0319
0.0312
0.0306
0.0299
0.0293
0.0287
0.0281
0.0275
0.0270
0.0265
0.0259
0.0254
0.0249
0.0244
°C
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
SLOPE
ZERO °C

17
16
PROBE & MEMBRANE MAINTENANCE
The D.O. probe body is made of reinforced
plastic for maximum durability.
A thermistor temperature sensor provides tem-
perature 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 sshown
in figure 1.
• Unscrew the membrane
by turning it counter-
clockwise (see fig.2)
• Wet the sensor by
soaking the bottom (2.5
cm / 1") of the probe in
HI 7041S electrolyte
solution for 5 minutes.
• Rinse the new mem-
brane (HI 76407A, sup-
plied with the meter)
with some electrolyte
while shaking gently.
Refill with clean elec-
trolyte.
• 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.
TWIST
AND
PULL
fig. 1
TAKING MEASUREMENTS
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 move-
ment of at least 0.3 m/sec is
required.
This movement will ensure that the oxygen-
depleted membrane surface is constantly re-
plenished. A moving stream will provide ad-
equate circulation.
To quickly check if the water speed is suffi-
cient, wait for stable reading and then move
the D.O. 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. Ac-
curate 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 tem-
perature difference of several degrees).

19
18
BATTERY REPLACEMENT
When the battery level is
low, a "V" will be displayed
to warn the user that the
battery should be replaced.
The meter will still work for approximately 4
hours, then the display will be shut-off to
avoid erroneous readings.
Battery replacement must only take place in
a safe area and using the battery type speci-
fied in this instruction manual.
Slide off the battery cover on the rear of the
meter and replace the 9V battery with a new
one.
V
BATTERY
• With the sensor facing down, screw the
membrane cap clockwise. Some electro-
lyte will overflow.
The Platinum cathode (#8 in the Functional
Description at page 4) 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 dam-
aged 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 plati-
num 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 is in perfect condi-
tion. 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 imper-
fection 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.