Milwaukee MW190 User manual

INSTRUCTION MANUAL
SATISFACTION
GUARANTEED
MW190
DO / Temperature
Bench Meter

All rights are reserved. Reproduction in whole or in part is prohibited without the written
consent of the copyright owner, Milwaukee Instruments Inc., Rocky Mount, NC 27804 USA.
THANK YOU for choosing Milwaukee Instruments!
This instruction manual will provide you the necessary information for correct use
of the meters.

3
TABLE OF CONTENTS
1. FUNCTIONAL DESCRIPTION......................................................................................................................................4
2. GENERAL DESCRIPTION.............................................................................................................................................6
3. SPECIFICATIONS............................................................................................................................................................. 7
4. PROBE FUNCTIONAL DESCRIPTION....................................................................................................................8
5. PROBE CONNECTION & PREPARATION..............................................................................................................9
6. OPERATIONAL GUIDE.................................................................................................................................................10
7. SALINITY AND ALTITUDE COMPENSATION ...................................................................................................... 11
8. D.O. MEASUREMENTS................................................................................................................................................12
9. TEMPERATURE MEASUREMENTS.......................................................................................................................12
10. D.O. CALIBRATION ......................................................................................................................................................13
11. LOGGING...........................................................................................................................................................................16
12. SETUP ..............................................................................................................................................................................20
13. TEMPERATURE CALIBRATION (for technical personnel only)........................................................24
14. PC INTERFACE.............................................................................................................................................................25
15. PROBE MAINTENANCE........................................................................................................................................... 27
16. TROUBLESHOOTING.................................................................................................................................................28
17. ACCESSORIES...............................................................................................................................................................29
CERTIFICATION..................................................................................................................................................................30
RECOMMENDATION........................................................................................................................................................30
WARRANTY..........................................................................................................................................................................30

4MW190 Bench Meter
1. FUNCTIONAL DESCRIPTION
DISPLAY
B
A
C
D
EF
G
H
I
A. Primary display
B. Measuring unit for primary display
C. Calibration messages
D. Setup, log mode
E. Require user confirmation
F. Calibration mode
G. Secondary display
H. Temperature unit
I. Calibration wrong message

FUNCTIONAL DESCRIPTION 5
FRONT PANEL
1. Liquid Crystal Display (LCD)
2. CAL key, to enter/exit calibration
mode
3. MR key, to enter/exit recall mode
4. ACCEPT key, to confirm value
5. LOG key, to store reading in memory
6. SETUP key, to enter/exit setup
mode or to toggle between delete
one and all logged data
7. key, to select SETUP item or to
decrease parameter value
8. RANGE key, to select measurement
unit/switch focused data
9. key, to select SETUP item or to
increase parameter value
10. ON/OFF key, to turn the meter ON
and OFF
11. Secondary LCD
12. Primary LCD
REAR PANEL
13. USB connector
14. RS232 connector
15. Power supply socket
16. DIN connector for probe
12
11
10
9
8
7
6
5
4
3
2
1
RS232
USB
Power
12Vdc
15
16
13
14

6MW190 Bench Meter
2. GENERAL DESCRIPTION
Thank you for choosing Milwaukee Instruments. This instruction manual will provide you
the necessary information for correct use of the meter.
MW190 is is a logging microprocessor-based DO and Temperature bench meter.
Dissolved Oxygen is indicated in ppm (parts per million) or in %.
All measurements are automatically compensated for temperature. Salinity compensation
in water allows direct determination of Dissolved Oxygen in saline waters and altitude
compensation readjusts for the altitude variance.
The Dissolved Oxygen probe has a membrane covering the polarographic sensors and a
built-in thermistor for temperature measurements and compensation.
This permeable Teflon® membrane isolates the sensor elements from the testing solution,
but allows Oxygen to pass through. When a voltage is applied across the sensor, oxygen
that has passed through the membrane reacts causing a current flow, and hence
determining a reading.
This Bench Meter is supplied with:
yMA840/2 DO probe
yMA841 membrane cap
yMA9071 electrolyte solution
yMA9315 Electrode Holder
yMi5200 Application Software
yMA9350 RS232 Connector cable (2 meters)
y12 VDC Adapter
yInstruction Manual

SPECIFICATIONS 7
3. SPECIFICATIONS
Range
DO
Temp
0.00 to 45.00 ppm O2
0.0 to 300.0 % O2
-5.0 to 55.0°C (23.0 to 131.0 °F)
Resolution
DO
Temp
0.01 ppm
0.1 %
0.1°C (0.1 °F)
Accuracy (@ 20°C / 68 °F) DO
Temp
±1.5 % of full scale
±0.4°C (±0.8 °F)
Calibration DO
Temp
single or double point at 0% (MI 9070) and 100% (in air)
2-point, at 0 and 50°C (32.0 and 122.0 °F)
Altitude Compensation
Resolution
0 to 4 000 m (13 120’)
100 m (328’)
Salinity Compensation
Resolution
0 to 40 g/l
1 g/l
Temperature Compensation Automatic, from 0.0 to 50.0°C (32.0 to 122.0 °F)
Probe MA840/2
Computer Interface RS232/USB opto-isolated
Power supply 12 VDC power adapter
Dimensions 230 x 160 x 95 mm (9.0 x 6.3 x 3.7”)
Weight 0.9 kg (2.0 lb.)
Environment 0 to 50°C (32 to 122 °F) ; max RH 95%
Warranty 3 years
This instrument is in compliance with the CE Directives.

8MW190 Bench Meter
4. PROBE FUNCTIONAL DESCRIPTION
7
8
10
9
3
4
1
2
4
5
6
1. D.O. Probe
2. Protective Cap
3. Watertight Shielded Cable
4. Polypropylene Probe Body
5. Temperature Sensor
6. O-Ring Seal
7. Silver Chloride Anode
8. Platinum Cathode (sensor)
9. Oxygen Permeable Teflon® Membrane
10. Membrane Cap

PROBE CONNECTION & PREPARATION 9
5. PROBE CONNECTION & PREPARATION
To take measurements, connect the D.O. probe to the meter securely by aligning the pins
with the socket located on the back of the meter, pushing the plug in and tightening the
threaded ring.
Probes shipped from Milwaukee Instruments are dry. To hydrate the probe and prepare it
for use, connect it to the meter and proceed as follows:
1. Remove the red and black plastic cap. This cap is for
shipping purposes and can be thrown away.
2. Wet the sensor by soaking the bottom 2½ cm (1”) of the
probe in electrolyte (MA9071) for 5 minutes.
3. Rinse the membrane cap (MA841 supplied in the kit
with the meter) with electrolyte solution while shaking
it gently. Refill with clean electrolyte solution.
4. Tap gently the sides of the membrane cap with your
finger tip to ensure that no air bubbles are trapped. To
avoid damaging the membrane, do not tap it directly
on the bottom.
5. Make sure that the rubber O-ring sits properly inside
the membrane cap.
6. With the sensor facing down, slowly screw the cap
clockwise. Some electrolyte will overflow.
When not in use and during polarization (see OPERATIONAL GUIDE), use the protective
transparent cap supplied in the kit with the meter.
Shipping
cap
black
red
FILL FIRST

10 MW190 Bench Meter
6. OPERATIONAL GUIDE
Plug the 12 VDC adapter into the power supply socket.
Connect the DO probe to the 7-pin connector. Make sure the probe sleeve is properly
inserted and tighten the threaded ring.
Turn the instrument on by pressing ON/OFF. All LCD tags are displayed and a beep is
heard while the instrument performs a self test.
yAfter a few seconds “Cond” message appears on the LCD to inform the user that the
probe is in auto-conditioning (automatic polarization) mode.
yWhen this message disappears, the probe is polarized and the instrument can be
calibrated.
yIf the probe is disconnected, the meter will display “----”.
PROBE POLARIZATION
The probe is under polarization with a fixed voltage of approximately 800 mV.
Probe polarization is essential for stable measurements with the same recurring degree
of accuracy.
With the probe properly polarized, oxygen is continually consumed when it passes
through the sensitive diaphragm and dissolves in the electrolyte solution contained in
the probe.
If polarization is interrupted, the electrolyte solution continues to be enriched with oxygen
until it reaches an equilibrium with the surrounding solution.

SALINITY AND ALTITUDE COMPENSATION 11
Whenever measurements are taken with a non-polarized probe, the oxygen level revealed
is both that of the tested solution, as well as that present in the electrolyte solution. This
reading is incorrect.
The calibration of this instrument is very simple.
Before proceeding with the calibration, make sure the probe is ready for measurements
(see PROBE CONNECTION & PREPARATION), i.e. the membrane cap is filled with electrolyte
and the probe is connected to the meter and properly polarized.
For an accurate calibration, it is recommended to wait at least 15 minutes to ensure
precise conditioning of the probe.
Keep the protective cap on during polarization time and remove it for calibration and
measurements. Follow the calibration procedure (see D.O. CALIBRATION).
7. SALINITY AND ALTITUDE COMPENSATION
If the sample contains significant concentration of salinity or if you are performing
measurements at an altitude dierent from sea level, the read out values must be
corrected, taking into account the lower degree of oxygen solubility in these situations
(see SETUP).
Remember to set the altitude and/or the salinity before taking any D.O. measurements.
The meter will automatically compensate for these factors.

12 MW190 Bench Meter
8. D.O. MEASUREMENTS
Make sure that the instrument has been calibrated and the protective cap has been
removed.
yImmerse the tip of the probe in the sample to be tested. Allow
approximately one minute for the reading to stabilize.
yThe Dissolved Oxygen value (in %) is displayed on the primary LCD and the temperature
on the secondary LCD.
yPress RANGE to change the reading from % to ppm and vice-versa.
For accurate Dissolved Oxygen measurements, a water movement of 0.3 m/s is required.
This is to ensure that the oxygen-depleted membrane surface is constantly replenished.
A moving stream will provide adequate circulation.
The use of a magnetic stirrer to ensure a certain fluid velocity is recommended.
9. TEMPERATURE MEASUREMENTS
The probe has a built-in temperature sensor.
The measured temperature is indicated on the secondary LCD as shown above.
Allow the probe to reach thermal equilibrium before taking any measurement. This can
take several minutes. The greater the dierence between the temperature at which the
probe was stored and the temperature of the sample, the longer the time will be.
Note: If “----” is displayed, the D.O. probe is not properly connected or the temperature
is out of range. This also indicates the posibility of a broken probe cable.

D.O. CALIBRATION 13
10. D.O. CALIBRATION
Calibrate the instrument frequently, especially if high accuracy is required.
The instrument can be calibrated in maximum 2 points: 0.0% (zero calibration) and
100.0% (slope calibration).
The zero calibration of the MW190 is very stable, therefore this procedure needs to be
performed only whenever the probe or the membrane is replaced.
However, because the slope calibration is more critical, it is recommended to perform this
procedure every week.
INITIAL PREPARATION
yPour small quantities of MA9070 Zero Oxygen solution into a
beaker. If possible, use a plastic beaker to minimize any EMC
interferences.
yMake sure the probe is ready for measurements (see PROBE
CONNECTION & PREPARATION), i.e. the membrane is filled with
electrolyte and the probe is connected to the meter.
ySwitch the meter on by pressing the ON/OFF switch.
yFor an accurate calibration, it is recommended to wait for at
least 15 minutes to ensure precise conditioning of the probe.
yRemove the protective cap from the D.O. probe.
ySet the appropriate altitude factor. Make sure the salinity
factor is set to zero. See SETUP section for details.
ZERO CALIBRATION
ySubmerge the probe into MA9070 zero oxygen solution and
stir gently for 2-3 minutes.
yPress CAL. The “WAIT” tag will blink on the LCD until the reading is stable.
MI9070
MI9070

14 MW190 Bench Meter
yWhen the reading is stable, “READY” & “ACCEPT” tags start blinking. Press ACCEPT to
confirm the “0.0%” D.O. calibration.
yIf the reading is within the limits (±15% f.s.), the meter stores the value (and adjusts
the zero point).
yPress CAL. The instrument will return to measurement mode and will memorize the
zero calibration data. For a two-point calibration do not press CAL and follow the
procedure below.
SLOPE CALIBRATION
It is suggested to perform the slope calibration in air.
yRinse the probe in clean water to remove any residual zero oxygen solution.
Note: If you did not perform the zero calibration procedure, press CAL and then the
ARROW keys to select the 100% D. O. calibration point.
yDry the probe tip and allow a few seconds for the LCD reading to stabilize. The “WAIT”
tag will blink until the reading is stable.

D.O. CALIBRATION 15
yWhen the reading is stable, “READY” & “ACCEPT” tags start blinking. Press ACCEPT to
confirm the “100.0%” D.O. calibration.
yIf the reading is within the limits (±15% f.s.), the meter stores the value (and adjusts
the slope point).
yThe instrument stores the slope calibration data and returns to measurement mode.
Notes:
If the reading is not close to the selected value, “WRONG“ & “BUFFER” tags will blink.
MW190 has automatic buer recognition function. If the ARROW keys are pressed
to select the desired calibration value, the automatic buer recognition function is
disabled.

16 MW190 Bench Meter
11. LOGGING
Up to 50 LOG samples can be stored into memory
LOGGING THE CURRENT DATA
To store the current reading into memory press the LOG key while in measurement mode.
The instrument will display the current date (MM.DD) on the primary LCD and the record
number on the secondary LCD, along with “LOG” tag (see example below: record No. 25,
dated June 29).
The instrument displays then the amount of free log space for about one second and
returns to normal measurement mode (e.g. 18 records free).
If there are less than 6 memory locations remaining, the record number and “Lo” message
will blink to alert the user.
If the log space is full, “FULL LOC” message will be displayed and no more data will be
saved.

LOGGING 17
When the LOG key is pressed while in measurement mode, a complete set of information
is stored.
VIEW LOGGED DATA
Press the MR key to retrieve the information stored while in measurement mode.
If no data were logged, the instrument displays “no rEC” message for the selected range.
Otherwise, the instrument will display the DO value on the primary LCD and the
temperature on the secondary LCD, along with last stored record number and “LOG” tag.
Pressing the arrow keys, the instrument will display the same parameter but for a dierent
record:

18 MW190 Bench Meter
Press the RANGE key and the instrument will display the next logged parameter:
yThe date: month and day on the primary LCD and the year on the secondary LCD,
along with “DATE” tag.
yThe time: hour and minutes on the primary LCD and the seconds on the secondary
LCD, along with “TIME” tag.
yThe salinity factor
yThe altitude factor

LOGGING 19
yThe “dEL” message on the primary LCD and the record number on the secondary LCD
along with “ACCEPT” tag blinking.
Notes:
If one of the arrow keys is pressed while “dEL” message is displayed, the next/previous
record number will be selected.
If the SETUP key is pressed, the secondary LCD will toggle between the record number
and “ALL” message.
Press the ACCEPT key to delete the selected or all records.
If “dEL ALL” option was selected, all records for the selected range are deleted and the
instrument returns to measurement mode.
After deleting a record, the “nuLL” message is displayed on the LCD for the selected
record.
Press the MR key to leave RECALL mode at any time.

20 MW190 Bench Meter
12. SETUP
Setup mode allows viewing and modifying the following parameters:
ySalinity Compensation
yAltitude Compensation
yCurrent Time (hh:mm)
yCurrent Date (MM.DD.YYYY)
yBeep Status
yBaud Rate (serial communication)
yInstrument ID
yTemperature Unit
To enter SETUP mode, press and hold the SETUP key for about 1 second while in normal
measurement mode.
Select the desired setup parameter using the UP and DOWN arrow keys.
Press the CAL key if you want to change the item value. The selected item (e.g. hour, in
setting up the correct time) and “ACCEPT” tag will start blinking.
Press the arrow keys to change the displayed value.
If there is another item to be set (e.g. minutes), press the RANGE key. The other item will
start blinking.
Press the arrow keys to change the displayed value.
Press the ACCEPT key to accept the value or the CAL key to escape.