Apera Instruments DO8500 User manual

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DO8500
Portable Optical Dissolved Oxygen Meter
Instruction Manual
APERA INSTRUMENTS (Europe) GmbH
www.aperainst.de
v1.2

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Table of Contents
1Overview..............................................................................................................................- 3 -
1.1 Luminescent optical sensor. ..........................................................................................- 3 -
1.2 Intelligent Instrumentation..............................................................................................- 3 -
2Technical Specifications .......................................................................................................- 4 -
3Instructions ..........................................................................................................................- 5 -
3.1 LCD Screen...................................................................................................................- 5 -
3.2 Key Operation ...............................................................................................................- 6 -
3.3 Batteries ........................................................................................................................- 7 -
3.4 Instrument Socket .........................................................................................................- 7 -
3.5 Display mode.................................................................................................................- 7 -
3.6 Data storage, recall, and clear. ......................................................................................- 8 -
3.7 Backlighting ...................................................................................................................- 8 -
3.8 Automatic Power-Off .....................................................................................................- 8 -
4Optical Dissolved Oxygen Probe..........................................................................................- 9 -
4.1 Probe Structure .............................................................................................................- 9 -
4.2 Probe Maintenance .......................................................................................................- 9 -
4.3 Sensor Cap .................................................................................................................- 10 -
5Preparation for Calibration .................................................................................................- 10 -
5.1 Dissolved Oxygen Units Selection...............................................................................- 10 -
5.2 Resolution Selection....................................................................................................- 11 -
5.3 Temperature Unit Selection .........................................................................................- 11 -
5.4 Air Pressure Compensation.........................................................................................- 11 -
5.5 Salinity Compensation.................................................................................................- 11 -
6Calibration..........................................................................................................................- 12 -
6.1 Saturated Oxygen Calibration......................................................................................- 12 -
6.2 Zero-Oxygen Calibration .............................................................................................- 12 -
6.3 Special Notes for Calibration .......................................................................................- 13 -
7Measurement .....................................................................................................................- 13 -
8Parameter Settings ............................................................................................................- 14 -
9USB Communication..........................................................................................................- 17 -
10 Complete Kit ......................................................................................................................- 19 -
10.1 What’s in the box.........................................................................................................- 19 -
10.2 Accessories for separate purchase..............................................................................- 19 -
11 Warranty...............................................................................................................................- 20 -
12 Trouble Shooting..................................................................................................................- 21 -
11 Appendix A: Oxygen Solubility Table (760mm Hg)..............................................................- 22 -
12 Appendix B: DO % Calibration Values................................................................................- 23 -

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Overview
Thank you for purchasing Apera Instruments DO8500 Portable Optical Dissolved Oxygen Meter. The
DO8500 measures dissolved oxygen in water using luminescence technology through an optical
sensor and displays data with intelligent instrumentation. Compared to conventional electrochemical
dissolved oxygen meter, the DO8500 is more accurate and stable, and easier to use.
Before you use the instrument, please carefully read the instruction manual to help you properly
perform tests and maintainenance.
1.1 Luminescent optical sensor.
Stability and Accuracy: Oxygen is not consumed during measurements. It is not affected by
sample flow rate and thus provides a stable measurement.
Easy to Use: No electrolytes and membranes are present in the meter; no warm-up required;
frequent calibration is not necessary.
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.
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.
Easy to calibrate and maintain. Probe is equipped with a calibration/storage sleeve, which
makes calibration and maintenance more convenient and reliable.
1.2 Intelligent Instrumentation
Built-in microprocessor chip, featured with Auto. Temperature Compensation, Auto. Air
Pressure Compensation, Auto. Salinity Compensation and parameter setting, auto. power off,
and low power indication.
Meter meets with the requirement of international GLP standards, clock display, manual
storage and automatic timing storage. USB data output.
Stable reading and automatic locking modes available.
Clear large-size LCD display with white backlight.
Meets IP57 waterproof rating; In addition, a rugged instrument suitcase is provided.
Special Notes
Sensor cap surface coating can not withstand high temperatures, so the optical
dissolved oxygen electrode can not test the water of more than 50 ℃.
When the electrode is not in use, it should be kept in the storage sleeve, and
keep the sponge in moist, so that the fluorescent cap will not dry out. If the
sponge is dry out or the probe is exposed in dry air for more than 8 hours, soak
the electrode in tap water for 24~48 hours (see article 4.2), otherwise it may
cause unstable measurements or slow response.
Before get readings or perform other operations, wait about 30 seconds after
meter is powered on.

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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 ±0.2 mg/L,
whichever is greater
±2% reading or ±2% saturation,
whichever is greater
Response Time
≤30 s (25℃ , 90% response)
Calibration Points
Saturation Point & Zero Oxygen
Temperature Compensation
Automatic, (0 to 50)℃
Pressure Compensation
Automatic, (60 to 120) kPa
Salinity Compensation
Manual or automatic, (0 to 45) ppt
Temperature
Range
(0 to 50.0)℃
Resolution
0.1 ℃
Accuracy
±0.5℃
Other
Data Storage
500 groups (with time and date)
Output
USB
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 & ISO9001:2015

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Instructions
3.1 LCD Screen
①
Measurement mode
⑨
Serial number of storage and
prompts of special display mode
②
Reading/Measured Value
⑩
M+ — Measurement to be stored
RM — Reading to be recalled
③
Timing storage
⑪
Temperature value and
prompts of special display mode
④
Date.time and prompts of
special display mode
⑫
Automatic reading lock-up
⑤
Units of date and time
⑬
ATC—Auto temperature compensation
MTC—Manual temperature compensation
⑥
Units of measurement
⑭
Stability icon of readings
⑦
Units of temperature
⑮
USB communication
⑧
Units during calibration
⑯
Low power indication
Fig.-1

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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.
First time use: see parameter setting P4.7 & P4.8 to set correct date and time (as Clause 8.3)
Special notes: Before get readings or do other operations, wait about 30 seconds after meter
powered on.
Table - 1 Key operation and functions
Key
Operation
Functions
Short Press
When powered off, press the key to power on
In measurement mode: press to turn backlight on or off
Long Press
Press and hold for 2 seconds to turn off
Short Press
In measurement mode: press the key to switch unit:
%→mg/L or %→ppm
Long Press
In the measurement mode:
press the key for 2 seconds to enter the calibration mode
Short Press
To cancel any operation, press to return to measurement mode
Short Press
In measurement mode: press to enter menu mode;
In calibration mode: press key to calibrate;
In the menu mode: press key to confirm the parameter.
Short Press
or
Long Press
In measurement mode: press key to change the serial
number or press to recall the measurement value.
In recall mode(RM), short press to change serial number of
stored measurement value, or long press to conduct rapidly
change;
In the menu mode:press the key to change the serial number or
select the parameter
Fig.-2

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3.3 Batteries
The instrument uses three AA alkaline batteries. Battery life > 200
hours (without backlight). When the display shows symbol as
shown in Figure-3, replace the battery.
3.4 Instrument Socket
The instrument socket protected by grey rubber sealing cap, as
shown in Figure-4.
Eight-pin socket (right) - connect DO electrode. 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.
BNC socket (left) - connect salinity electrode
RCA socket (middle) - connect temperature probe
3.5 Display mode
3.5.1 Main Display Screen
If the salinity probe is not connected or salinity is lower than 1ppt, only
the DO value and temp value will be displayed on the LCD screen as
shown in Figure-5, DO value: 8.18mg/L; temp. value: 25.2℃.
When salinity probe is connected and salinity is higher than 1ppt,
salinity will be displayed on right bottom of the LCD screen, as shown
in Figure-6,DO value: 6.97mg/L, Temp value: 25.2℃; Salinity: 32ppt,
Press key to switch beteen unit of mg/L→%. Or select unit of
mg/L or ppm
in parameter setting P3.1, time displays on top right of LCD screen.
3.5.2 Reading Stability Mode
When the measured value is stable, the LCD screen displays the icon
as shown in Figure-7. If there is no icon or icon flashing,
indicates that the measured value is not stable, the measured value
should not be read or calibrated.
3.5.3 Auto Lock Mode
In parameter setting P4.3 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 - 8.When auto
locked, press to unlock. Select Off to turn off automatic locking.
Fig.-3
Fig.-7
Fig.-8
Fig.-5
Fig.-6
Fig.-4

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3.6 Data storage, recall, and clear.
3.6.1 Manual storage
When the measurement is stable, press key, the meter will store
measureent value, M+ icon and storage serial number will be displayed
on botton right of LCD sreen, as shown in Figure-9. First group of data
was stored.If connect salinity probe, press key, M+ icon and
storage serial number will be displayed for 2 seconds, then salinity
displays on LCD screen continously. As shown in Figure-6
3.6.2 Automatic timing storage
Set the storage timing (e.g. 3 minutes) from parameter P4.1, icon
displays on LCD screen, the meter enters the timing storage mode.
When press key, icon flashes and the first measuring value
is stored. After 3 minutes, the 2nd measuring value is stored automaticly.
See Figure-10 the meter stores eight measuring values automatically.
When press key, icon stops flashing and the meter stops
automatic storage. In automatic storage mode, manual storage does
not work.
Set time 0 in parameter P4.1 to exit from the automatic storage mode.
3.6.3 Recall stored value
In the measurement mode, press key to recall the last stored
measured value. See Figure 11: Pressing key or key to
change the recalled measuring value. Press and hold
key or key to change the recalled measuring value quickly.
3.6.4 Clear stored value
Select YES in parameter P4.4 to clear all stored value.
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. There`s two backlighting mode. On and
Off, you can select in the parameter setting P4.5. Select On, press backlight will be on
for a minute then automatically shuts off. Select Off, when the key is pressed, backlight
will be on and will be off only when is pressed again.
3.8 Automatic Power-Off
In the parameter setting P4.6, you can set the auto power off function (On-Off), select On to
turn on auto power off function, the instrument will shut down automatically if no operation
within 20 minutes, select Off to disable this function.
Fig.-11
Fig.-10
Fig.-9

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Optical Dissolved Oxygen Probe
4.1 Probe Structure
The instruments DO803 optical dissolved oxygen probe has a cable length of 3m and a built-
in temperature sensor for automatic temperature compensation. The electrode structure is
as shown in Figure.-12
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/Storage sleeve
Immersion line:
The test sample 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.-12

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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 replace it 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.
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 probe calibration.