Apera Instruments DO850 User manual

- 1 -
DO850
Portable Optical Dissolved Oxygen Meter
Instruction Manual
APERA INSTRUMENTS, LLC
www.aperainst.com
v2.1

- 2 -
Table of Contents
1. Overview --------------------------------------------------------------------------------------------------
2. Technical Specifications -------------------------------------------------------------------------------
3. Instructions -----------------------------------------------------------------------------------------------
3.1 LCD Screen -----------------------------------------------------------------------------------------
3.2 Key Operation --------------------------------------------------------------------------------------
3.3 Batteries ---------------------------------------------------------------------------------------------
3.4 Instrument Socket ---------------------------------------------------------------------------------
3.5 Reading Stability Mode ----------------------------------------------------------------------------
3.6 Auto Lock Mode -------------------------------------------------------------------------------------
3.7 Backlighting ------------------------------------------------------------------------------------------
3.8 Automatic Power-Off ------------------------------------------------------------------------------
4. Optical Dissolved Oxygen Probe -------------------------------------------------------------------
4.1 Probe Structure -------------------------------------------------------------------------------------
4.2 Probe Maintenance ----------------------------------------------------------------------------------
4.3 Sensor Cap ------------------------------------------------------------------------------------------
5. Preparation for Calibration ---------------------------------------------------------------------------
5.1 Dissolved Oxygen Units Selection ------------------------------------------------------------
5.2 Resolution Selection ------------------------------------------------------------------------------
5.3 Temperature Unit Selection ---------------------------------------------------------------------
5.4 Air Pressure Compensation ----------------------------------------------------------------------
5.5 Salinity Compensation-------------------------------------------------------------------------------
6. Calibration ------------------------------------------------------------------------------------------------
6.1 Saturated Oxygen Calibration --------------------------------------------------------------------
6.2 Zero -Oxygen Calibration --------------------------------------------------------------------------
6.3 Special Notes for Calibration ---------------------------------------------------------------------
7. Measurement ----------------------------------------------------------------------------------------------
8. Parameter Settings ---------------------------------------------------------------------------------------
9. Complete Kit -----------------------------------------------------------------------------------------------
10. Warranty ----------------------------------------------------------------------------------------------------
11. Trouble Shooting -----------------------------------------------------------------------------------------
Appendix A: Oxygen Solubility Table (760mm Hg)----------------------------------------------- !
Appendix B: DO% Calibration Values --------------------------------------------------------------
3!
4!
4!
4!
5!
6!
6!
6!
6!
6!
6!
7!
7!
7!
8!
8!
8!
8!
9!
9!
9!
9!
9!
9!
10!
10!
11!
13!
13!
14!
15!
16!

- 3 -
1 Overview
Thank you for purchasing Apera Instruments DO850 Portable Optical Dissolved Oxygen
Meter. The DO850 measures dissolved oxygen in water using luminescence technology
through an optical sensor and displays data using advanced intelligent instrument.
Compared to electrochemical oxygen analyzers, the DO850 is more accurate and stable,
easier to use and cost-effective portable dissolved oxygen meter.
Before you use the instrument, please carefully read the instruction manual to help you
properly use and maintain.
1.1 Luminescent optical sensor.
l Stability and Accuracy: Oxygen is not consumed during measurements. It is not
affected by sample flow rate and thus provides a stable measurement.
l Easy to Use: No electrolytes and membranes are present in the meter; no warm-up;
frequent calibration is not necessary.
l Interference-Free: Sensor cap is coated with a light-shielding layer and minimizes the
impact from external light sources. The use of non-chemical sensors helps reduce a
variety of heavy metal ions interference in the aqueous environment, along with H2S
and NH4 and other chemical substances.
l Long service life. Other than mechanical deterioration (such as scratches to the light
shielding layer), the sensor cap has up to 8000 hours of service life.
l Easy to Calibrate and Maintain. Probe is equipped with calibration/storage sleeve,
which makes calibration and maintenance more convenient and reliable.
1.2 Advanced Intelligent Instrument
l Automatic temperature compensation, automatic pressure compensation and manual
salinity compensation.
l Clear large-size LCD display with white backlight.
l Reading stable and automatic locking modes.
l Meets IP57 waterproof rating; in addition, a standard instrument suitcase is provided.
Special Notes
lSensor cap surface coating can not withstand high temperatures, so the
optical dissolved oxygen electrode can not test the water of more than 50 ℃.
lSensor cap must be kept in a humid environment, if the surface coating is
dry, treat it by hydration, otherwise the measured value is unstable or the
response is slow, as described in section 4.2 (Probe Maintenance)
lAfter meter power on, wait about 30 seconds to read value or operatation.

- 4 -
2 Technical Specifications
Dissolved
Oxygen
Dynamic Range
(0-20.00) mg/L (ppm), (0-200.0)%
Resolution
0.01/0.1mg/L (ppm), 0.1/1%
Accuracy
±2% reading or ±2% saturation,
whichever is greater
±2% reading or ±0.2 mg/L,
whichever is greater
Response Time
≤30 s (25℃ , 90% response)
Calibration Points
Saturation Point & Zero Oxygen
Tem pera tu re Co mpen sa tion
Automatic, (0 to 50)℃
Pressure Compensation
Automatic, (60 to 120) kPa
Salinity Compensation
Manual, (0 to 45) ppt
Temperature
Range
(0 to 50.0) ℃
Resolution
0.1 ℃
Accuracy
±0.5 ℃
Other
Batteries
AA x 3 (1.5V×3)
IP Rating
IP57
Dimensions and Weight
Meter: 88×170×33 mm/313g
With case: 360×270×76 mm/1.3kg
Product Certificate
RoHs, CE & ISO9001:2008
3 Instructions
3.1 LCD Screen
Fig.-1

- 5 -
3.2 Key Operation
Short press: key press time < 2 s; Long press: key press time> 2 s.
Power on: Press to turn on. Shutdown: long press 2 seconds off.
Special notes: After meter power on, wait about 30 seconds to read value or operatation.
Tabl e - 1 Key operation and functions
Key
Operation
Functions
Short
Press
l In the shutdown mode: press the key to boot
l In measurement mode: press to turn backlight on or off
Long Press
l Press and hold for 2 seconds to turn off
Short
Press
l In measurement mode: press the key to switch unit: %→mg/L
or %→ppm
Long Press
l In the measurement mode: press the key for 2 seconds to enter the
calibration mode
Short
Press
l To cancel any operation, press to return to measurement mode
Short
Press
l In the menu mode: press the key to change the serial number or
select the parameter
Short
Press
l In the menu mode: press the key to change the serial number or
select the parameter
①!
Measurement mode icon
⑦!
Auto lock icon
②!
Reading/Measured Value
⑧!
Tem pera tu re Co mpen sa tion
ATC — Auto Temperature Compensation
MTC — Manual Temperature Compensation
③!
Symbol
④!
Units of Measurement
⑤!
Tem pera tu re un it
⑨!
Reading Stability Icon
⑥!
Tem prat ure v al ue / Symbol
⑩!
Low Voltage Icon
Fig.-2

- 6 -
Short
Press
l In measurement mode: press to enter menu mode;
l In calibration mode: press key to calibrate;
l In the menu mode: press key to confirm the parameter.
3.3 Batteries
The instrument uses three AA batteries, please use the LR6-type
alkaline batteries to ensure battery quality. Battery life> 200 hours (no
backlight). When the display shows symbol as Figure-3, replace
the battery.
3.4 Instrument Socket
The instrument uses an 8-pin socket that is protected by a gray rubber cap seal. When
inserting the Probe plug, please insert it after the notch position, and tighten the plug nut.
The end face of the socket and the plug connection has the sealing ring, which can
effectively maintain the waterproof protection of the socket.
3.5 Reading Stability Mode
When the measured value is stable, the LCD screen displays the icon
as shown in Figure-4. If there is no icon or icon flashing,
indicating that the measured value is not stable, the measured value
should not be read or calibrated.
3.6 Auto Lock Mode
In parameter setting P4.2 you can select the auto-lock mode (Off-On),
select On to turn on automatic locking. When the reading is
stable for more than 10 seconds, the meter automatically locks the
measured value and displays the HOLD icon, as shown in Figure 5.
When auto locked, press to unlock.
3.7 Backlighting
The Instruments LCD screen has a white backlight suitable for use in dimly lit environments.
Turning on the backlight will consume more power. The instrument is equpped with
automatic backlight and manual backlight mode. In automatic backlight mode, when
thepower key is pressed, backlight will be on for a minute then automatically shuts off;
In manual backlight mode, when the key is pressed, backlight will be on and will be off
only is pressed again. In the parameter setting P4.3, you can select the auto backlight
mode (On-Off), select On to turn on auto backlight, select Off to turn off auto backlight.
3.8 Automatic Power-Off
In the parameter setting P4.4, you can select the auto power off function (On-Off), select On
to turn on auto power off, the instrument will shut down automatically after 20 minutes, select
Off to disable this function.
Fig.-3
Fig.-4
Fig.-5

- 7 -
4 Optical Dissolved Oxygen Probe
4.1 Probe Structure
The instruments DO803 optical dissolved oxygen probe has a cable length of 3m and built-
in temperature sensor for automatic temperature compensation. The electrode structure is
shown in Fig.-6
1. Bottom cover of the calibration sleeve
5. Locking cap
2. Sponge for water storage
6. Optical DO electrode
3. Sensor cap
7. O ring
4. Calibration sleeve
Immersion line:
The tested solution should be above this line
4.2 Probe Maintenance
The sensor cap of the optical DO electrode must be kept in a moist environment. If the
surface coating of the sensor cap dries out, the measured value will be unstable or the
response will be slow. The electrode calibration sleeve is used to store the probe.
(A) Short-term storage (less than 30 days): The probe head is kept in the calibration
sleeve. Always keep the sponge inside the calibration sleeve wet. Several drops of
clean water should be added to a dry sponge (let the sponge be saturated, but not
dripping), and tighten the lock cap, so that the sensor cap is kept in the moist-
saturated air.
(B) Long-term storage (greater than 30 days): The probe head is kept in the calibration
sleeve. Check whether the water storage sponge is moist every 30 days or user can
store the electrode in a beaker containing water.
(C) Before the first use, unscrew the calibration sleeve to check if the sponge is wet. If the
sponge is dry or if the electrode is exposed to dry air for more than 8 hours, the
surface coating of the sensor cap may be completely dry. So the electrode should be
Fig.-6

- 8 -
immersed in tap water at room temperature 25℃ for 24 hours. If the water temperature
is low, soaking time is 48-72 hours.
(D) The sponge can not be allowed to get stained or moldy, otherwise it will consume or
produce oxygen. If stained or moldy, please clean immediately.
4.3 Sensor Cap
(A) The sensor cap is an important part of the optical DO probe. The surface coating of
the cap cannot be scratched or mechanically worn. Otherwise, the life of the sensor
cap will be reduced or the probe will be damaged. Please pay special attention to it
when using the probe.
(B) The surface coating of the sensor cap cannot withstand high temperatures, so the
optical DO probe can not be tested in water above 50 ℃.
(C) If the surface of the sensor cap is contaminated, please do not use alcohol and
organic solvents to clean, otherwise it may damage the probe. It can be gently wiped
with a soft cloth or paper towels. To disinfect the probe, immerse it in 3% hydrogen
peroxide for 15 to 30 minutes and then rinse off with water.
(D) The sensor cap has a service life of more than 8000 hours. When the probe is not
being used, it does not "bleach" luminescence layer; in addition, the storage time will
not reduce the life of the probe, so the actual use time of the sensor cap is far more
than a year. The major factor affecting the service life of the sensor cap is the surface
coating being damaged under external force. So the key is to protect the sensor cap
from external damage.
(E) If the sensor cap is damaged or deteriorated, users need to purchase a new one.
Every new cap has a set of calibration codes which need to be input into the
instrument. The specific input method will be described in the instruction manual of
sensor cap.
(F) The probe that comes with the instrument can be used directly without the input of the
calibration codes. So users should not take off the sensor cap when it is not in use.
Nor should one swap the caps from different instruments. When being installed, the
sensor cap must be tightened and the interior can not be contaminated or wet.
5 Preparation for Calibration
5.1 Dissolved Oxygen Units Selection
Dissolved oxygen units displays in two forms: mg / L and %, and ppm and %. Press to
switch between mg / L → %, or ppm → %. Users can choose mg / L or ppm in parameter
setting P3.1, but only a percentage (DO %) is displayed in calibration.

- 9 -
5.2 Resolution Selection
The resolution unit can be selected in parameter setting P3.2: 0.01 or 0.1mg/L (ppm). After
setting, the meter will display resolution of 0.1 or 1 in according to %.
5.3 Temperature Unit Selection
The temperature unit can be selected in parameter setting P4.1: ℃ or ℉.
5.4 Air Pressure Compensation
The instrument has automatic air pressure compensation function. The instrument has been
performed the air pressure calibration before it leaves the factory. So generally users do not
have to calibrate the air pressure. If necessary, calibrate it according to the value of the
standard barometer. Refer to parameter setting P3.4 for the procedure of barometric
calibration.
5.5 Salinity Compensation
The instrument has manual salinity compensation. It is set in the parameter P3.3 (0 to 45
ppt). To obtain accurate readings in mg/L and ppm, it is necessary to know the salinity of the
solution to be tested and input it into the instrument. As the salinity of the solution increases,
the level of DO decreases. Generally, salinity of freshwater is 0 to 0.5ppt, salinity of seawater
is 35ppt.
6 Calibration
6.1 Saturated Oxygen Calibration
(A) This procedure requires the use of a calibration sleeve to allow the probe to be calibrated
in a humidity-saturated atmosphere
(B) Check that the sponge in the calibration sleeve is wet. Attach the calibration sleeve to
the probe. Tighten the locking cap. Be careful not to have water droplets on the head of
the cap. Wait for 5 to 10 minutes after turning on the instrument. Saturate the air in the
calibration sleeve with water vapor. In addition, wait for the temperature to completely
stablize.
(C) Long press the key to enter the calibration mode, and the CAL is flashing in the
upper right corner of the LCD. Wait for the stable icon to appear and stay, press the
key to calibrate, once the instrument displays a stable 100%, it is ready to use.
6.2 Zero -Oxygen Calibration
Zero-Oxygen calibration is only performed when a probe or sensor cap is replaced or the
probe has not been used for a long period. It is usually not necessary to conduct zero oxygen
calibration. The instrument is factory calibrated for zero oxygen, so it is not necessary to
perform a zero-oxygen calibration for the first time. Zero-oxygen calibration should follow
these steps:

- 10 -
(A) Preparation of 100ml of oxygen-free water: in the 100ml beaker weigh 2g anhydrous
sodium sulfite (Na2SO3) and add 100ml of pure water or tap water to dissolve.
Oxygen-free water is effective within 1 hour.
(B) Put the electrode into the oxygen-free water, wait for 3 to 5 minutes after the
instrument is turned on, and wait for the temperature and measured value to
completely stabilize. The measured value should be very low, 0.1mg / L or so.
(C) Long press to enter the calibration mode. The upper right corner of the LCD will
flash CAL. Wait for a stable icon. Press and the zero-oxygen calibration is
completed.
6.3 Special Notes for Calibration
(A) Optical dissolved oxygen probes have better stability and smaller calibration drift
compared to conventional electrochemical dissolved oxygen electrodes, which means
that the instrument can maintain its calibration data for a few months. However, for better
accuracy, it is recommended that the oxygen saturation calibration be performed
according to section 6.1 before use every day.
(B) Drying of the surface coating of the sensor cap can adversely affect the stability of the
measurement. Please pay special attention to this situation. See Section 4.2 (Probe
Maintenance) for details.
(C) The instrument has factory default setting function, select YES in parameter setting P3.5,
the meter will be calibrated to the theory value.
7 Measurement
7.1 When measuring, place the probe in sample solution, swirl quickly in the solution for a
few seconds and rest it to remove bubbles from the measuring surface of the sensor cap.
The solution must be above the immersion line of the probe. Note that brief shaking the
probe in solution is only to eliminate bubbles. Not like conventional electrochemical
electrodes, the measuring via optical dissolved oxygen probes does not require constant
stirring of the solution or flowing fluid.
7.2 Users can read the measured values when the icon appears and stays. Note that
the measurement time is related to temperature. When the solution temperature and the
probe temperature is close, the measurement time is about one minute. When the solution
temperature and the electrode temperature differ a lot, it takes about 3 minutes to reach a
stable reading. This is because the reading of dissolved oxygen is heavily influenced by
temperature, and the probe senses temperature much more slowly than dissolved oxygen.

- 11 -
8 Parameter Settings
8.1 Press the key in the measurement mode to enter the parameter setting mode P3.0,
press the key to switch the menu P3.0 →P4.0; In P3.0 mode, press to enter
P3.1, press to switch submenu P3.1→P3.5; In P4.0 mode, press to enter P4.1,
press to switch submenu P4.1→P4.4. See Table 2 for details.
Tabl e-2 Parameter Setting List
Menu
Submenu
Parameter
Code
Content
P3.0
DO
parameter
P3.1
DO Units Selection
/
mg/L—ppm
P3.2
Resolution Selection
/
0.01/0.1 mg/L(ppm)
P3.3
Salinity Compensation
/
(0 to 45) ppt
P3.4
Air Pressure Calibration
(60 to 120) kPa
P3.5
Back to Factory Default
No—Yes
P4.0
Basic
parameter
P4.1
Tem p. Unit Selection
/
℃—℉
P4.2
Auto Lock
/
Off—On
P4.3
Auto Backlight
On—Off
P4.4
Auto Power Off
On—Off
8.2 DO Parameter setting (press or to switch)
P3.1—Dissolved Oxygen Unit (mg/L—ppm)
1. In P3.0 mode, press the key to enter P3.1 mode.
2. Press the key, mg / L flashes, press the key to select
mg/L → ppm, press to confirm.
3. Press to enter P3.2 mode, or press to return to
measurement mode.
P3.2—Resolution (0.01-0.1mg/L)
1.Press the key, 0.01 flashes, press the key to select
resolution (0.01-0.1mg/L),press to confirm.
2. Press to enter P3.3 mode, or press to return to
measurement mode.

- 12 -
P3.3—Salinity Compensation (0~45 ppt)
1. Press the key, 0 flashes, Press or key to adjust
salinity value (0 to 45 ppt), Press Key to confirm.
2. Press to enter P3.4 mode,or press to return to
measurement mode.
P3.4—Air Pressure Calibration (60 to 120 kPa)
1. Press the key, 101.3 flashes, according to standard pressure
value. Press or key to adjust, Press key to confirm.
2. Press to enter P3.5 mode, or press to return to
measurement mode.
P3.5—Back to Factory Default (No—Yes)
Press key, No flashes, Press key to select No →Yes,
Press key to confirm. Meter returns to measurement mode.
No—cancel restore. Yes—restore
8.3 Basic Parameter setting (press or to switch)
P4.1— temperature unit (℃—℉)
1. In P4.0 mode, Press key to enter P4.1 mode.
2. Press key, ℃ flashes, Press key to select ℃→℉, Press
key to confirm.
2.Press key to enter P4.2 mode, or key to return to
measurement mode.
P4.2—Auto Lock (Off—On)
1. Press key, Off flashes, Press key to select Off→On, Press
key to confirm. Off—unlock; On—lock (If reading stays stable
for more than 10seconds, it auto locks).
2. Press key to enter P4.3 mode, or key to return to
measurement mode.
P4.3—Auto Backlight (On—Off)
1. Press key, On flashes, Press key to select On→Off, Press
key to confirm. On - Auto backlight on, Off - Auto backlight off.
2. Press key to enter P4.4 mode, or press key to return to
measurement mode.
P4.4—Auto Power Off (On—Off)
1. Press key, On flashes，Press key to select On→Off,press
key to confirm.
On—auto power off on
，
Off—auto power off off
2. Press key to return to measurement mode.

- 13 -
9 Complete Kit
9.1 What’s in the box
Content
Quantity
1.
DO850 Portable Optical Dissolved Oxygen Meter
1
2
DO803 Optical Dissolved Oxygen Probe
1
3
Probe Calibration Sleeve
1
4
Small Screwdriver
1
5
Carrying Case
1
6
Sponge for Water Storage (spare)
4
7
Instruction Manual
1
9.2 Accessories for separate purchase
10 Warranty
10.1 The warranty period of the DO850 instrument (only the instrument) is 3 years from the
date of purchase. That of DO803 optical DO probe (excluding sensor cap) is 2 years from
the date of purchase. That of DO8032 sensor cap is 1 year from the date of purchase. If the
above products or parts within the warranty period is not functional due to raw material
defects or poor manufacturing, they are free for repair or replace.
10.2 Damage and malfunction of the product caused by the following reasons are not
covered by the warranty:
(A) Fails to install, operate, or use the product in accordance with the instruction manual, or
if the product is damaged by abuse or incorrect use;
(B) The sensor cap is damaged by external force and can not work; or the electrode cable
is damaged or twisted due to external force;
Model
Name
DO803
Optical DO probe（3m cable，with sensor cap and calibration sleeve）
DO810
Optical DO probe（10m cable, with sensor cap and calibration sleeve）
DO8032
Sensor cap
DO8031
Calibration sleeve

- 14 -
(C) Fails to maintain the product in accordance with the requirements of this manual and
the industry standard process;
(D) Any unauthorized repairs, and the use of defective or incorrect components to repair the
product;
(E) Any modification of the product unauthorized by the Company.
10.3 Product Warranty Period is the free of charge service time for the user who purchase
the product, not the service life of the instrument or the probe.
11 Trouble Shooting
Error
Solutions
The instrument does
not turn on
1. The battery is not installed correctly. Check the polarity.
2. Battery low voltage, replace the battery.
3. Instrument freezes. Unplug the battery and then install.
The instrument can
not calibrate
1. Check calibration procedure: correct atmospheric pressure,
salinity input and temperature.
2. The measured value is not stable, prolong the stabilization
time, until the demonstration then presses the key.
3. Check the sensor cap. If it is contaminated, it can be cleaned; if
dry, it can be hydrated; if damaged it can be replaced.
DO readings are not
accurate
1.Check whether the temperature is stable, the salinity input and
barometric pressure are accurate.
2. If the probe calibration is not good, recalibrate.
3. Check the sensor cap. If it is contaminated, it can be cleaned;
if dry, it can be hydrated; if damaged it can be replaced.
4. Unscrew the sensor cap, check whether there is moisture
inside, if so, wipe off, dry, and tighten it.
The display value
stays 200% or
20.0 mg/L. No
change
1. Check whether the concentration of the sample is higher than
200% or 20.0 mg / L (ppm).
2. Check if the temperature reading is accurate.
3. If the probe calibration is not good, recalibrate.
4. Check the sensor cap. If it is contaminated, it can be cleaned; if
dry, it can be hydrated; if damaged, it can be replaced.

- 15 -
Appendix A: Oxygen Solubility Table (760mm Hg)
Temp °C
Chlority: 0
Salinity: 0
5.0 ppt
9.0 ppt
10.0 ppt
18.1 ppt
15.0 ppt
27.1 ppt
20.0 ppt
36.1 ppt
25.0 ppt
45.2 ppt
0.0
14.62
13.73
12.89
12.10
11.36
10.66
1.0
14.22
13.36
12.55
11.78
11.07
10.39
2.0
13.83
13.00
12.22
11.48
10.79
10.14
3.0
13.46
12.66
11.91
11.20
10.53
9.90
4.0
13.11
12.34
11.61
10.92
10.27
9.66
5.0
12.77
12.02
11.32
10.66
10.03
9.44
6.0
12.45
11.73
11.05
10.40
9.80
9.23
7.0
12.14
11.44
10.78
10.16
9.58
9.02
8.0
11.84
11.17
10.53
9.93
9.36
8.83
9.0
11.56
10.91
10.29
9.71
9.16
8.64
10.0
11.29
10.66
10.06
9.49
8.96
8.45
11.0
11.03
10.42
9.84
9.29
8.77
8.28
12.0
10.78
10.18
9.62
9.09
8.59
8.11
13.0
10.54
9.96
9.42
8.90
8.41
7.95
14.0
10.31
9.75
9.22
8.72
8.24
7.79
15.0
10.08
9.54
9.03
8.54
8.08
7.64
16.0
9.87
9.34
8.84
8.37
7.92
7.50
17.0
9.67
9.15
8.67
8.21
7.77
7.36
18.0
9.47
8.97
8.50
8.05
7.62
7.22
19.0
9.28
8.79
8.33
7.90
7.48
7.09
20.0
9.09
8.62
8.17
7.75
7.35
6.96
21.0
8.92
8.46
8.02
7.61
7.21
6.84
22.0
8.74
8.30
7.87
7.47
7.09
6.72
23.0
8.58
8.14
7.73
7.34
6.96
6.61
24.0
8.42
7.99
7.59
7.21
6.84
6.50
25.0
8.26
7.85
7.46
7.08
6.72
6.39
26.0
8.11
7.71
7.33
6.96
6.62
6.28
27.0
7.97
7.58
7.20
6.85
6.51
6.18
28.0
7.83
7.44
7.08
6.73
6.40
6.09
29.0
7.69
7.32
6.93
6.62
6.30
5.99
30.0
7.56
7.19
6.85
6.51
6.20
5.90
31.0
7.43
7.07
6.73
6.41
6.10
5.81
32.0
7.31
6.96
6.62
6.31
6.01
5.72
33.0
7.18
6.84
6.52
6.21
5.91
5.63
34.0
7.07
6.73
6.42
6.11
5.82
5.55
35.0
6.95
6.62
6.31
6.02
5.73
5.46
36.0
6.84
6.52
6.22
5.93
5.65
5.38
37.0
6.73
6.42
6.12
5.84
5.56
5.31
38.0
6.62
6.32
6.03
5.75
5.48
5.23
39.0
6.52
6.22
5.98
5.66
5.40
5.15
40.0
6.41
6.12
5.84
5.58
5.32
5.08
41.0
6.31
6.03
5.75
5.49
5.24
5.01
42.0
6.21
5.93
5.67
5.41
5.17
4.93
43.0
6.12
5.84
5.58
5.33
5.09
4.86
44.0
6.02
5.75
5.50
5.25
5.02
4.79
45.0
5.93
5.67
5.41
5.17
4.94
4.72
Salinity = Dissolved salts in water.
Chlorinity = Measure of chloride content, by mass, of water.
S (‰) = 1.80655 x Chlorinity (‰)

- 16 -
Appendix B: DO % Calibration Values
Cal.
value
Pressure
Cal.
value
Pressure
D.O. %
in Hg
mmHg
kPa
mbar
D.O. %
in Hg
mmHg
kPa
mbar
101%
30.22
767.6
102.34
1023.38
86%
25.73
653.6
87.14
871.40
100%
29.92
760.0
101.33
1013.25
85%
25.43
646.0
86.13
861.26
99%
29.62
752.4
100.31
1003.12
84%
25.13
638.4
85.11
851.13
98%
29.32
744.8
99.30
992.99
83%
24.83
630.8
84.10
841.00
97%
29.02
737.2
98.29
982.85
82%
24.54
623.2
83.09
830.87
96%
28.72
729.6
97.27
972.72
81%
24.24
615.6
82.07
820.73
95%
28.43
722.0
96.26
962.59
80%
23.94
608.0
81.06
810.60
94%
28.13
714.4
95.25
952.46
79%
23.64
600.4
80.05
800.47
93%
27.83
706.8
94.23
942.32
78%
23.34
592.8
79.03
790.34
92%
27.53
699.2
93.22
932.19
77%
23.04
585.2
78.02
780.20
91%
27.23
691.6
92.21
922.06
76%
22.74
577.6
77.01
770.07
90%
26.93
684.0
91.19
911.93
75%
22.44
570.0
75.99
759.94
89%
26.63
676.4
90.18
901.79
74%
22.14
562.4
74.98
749.81
88%
26.33
668.8
89.17
891.66
73%
21.84
554.8
73.97
739.67
87%
26.03
661.2
88.15
881.53
72%
21.54
547.2
72.95
729.54
APERA INSTRUMENTS, LLC
Address: 6656 Busch Blvd, Columbus Ohio 43229
Tel: [phone]
Email: [e-mail]
Website: www.aperainst.com