LT PO2-250 User manual

Pen type, air oxygen and Temp.
O2METER
Model : PO2-250
Y
our purchase of this
OXYGEN METER marks
a step forward for you
into the field o
f
precision measurement.
A
lthough this METER is
a complex and delicate
instrument, its durable
structure will allow
many years of use i
f
proper operating
techniques are
developed. Please read
the following
instructions carefully
and always keep this
manual within easy
reach.
OPERATION MANUAL

TABLE OF CONTENTS
1.FEATURES................................................................
.
1
2.SPECIFICATIONS......................................................
.
1
2-1 General Specifications..........................................1
2-2 Electrical Specifications........................................2
3.FRONT PANEL DESCRIPTION..................................... 4
3-1 Oxygen/Temp. Sensor.........................................
.
4
3-2 Power Button...................................................... 4
3-3 Hold Button........................................................
.
4
3-4 REC ( Max./Min. ) Button.....................................
.
4
3-5 LCD Display........................................................
.
4
3-6 Battery Compartment/Cover.................................4
4.MEASURING PROCEDURE.......................................... 5
4-1 O2 ( Air oxygen )/Temp. ( Air Temp. )
measurement..................................................... 5
4-2 Data hold............................................................5
4-3 Data Record ( Max., Min. reading)........................ 5
4-4 Auto power off.................................................... 6
4-5 Set the Temp. unit ( , ) with default..............℃℉ 6
5.CALIBRATION....................................................... 7
6.BATTERY REPLACEMENT...........................................
.
7

1. FEATURES
* O2 ( Air oxygen ) and Temp. ( Air Temp. ) measurement.
* O2 measurement range : 0 to 30.0 % x 0.1 %.
* O2 Buzzer warning : If the measurement value < 18.0
%O2, the buzzer will sound for warning.
* Temp. measurement range : 0 to 50 , / .℃℃℉
* Galvanic cell type for O2 sensor.
* High reliability Oxygen sensor, not be affected by
acidic gases like CO2.
* Oxygen sensor with temperature compensated.
* Data hold, to freeze the desired reading value.
* Auto power off saves battery life.
* Operates from DC 1.5V ( UM4/AAA ) x 4 PCs batteries.
* Microprocessor circuit ensure high accuracy, and also
and also provides special functions and features.
* Durable and compact ABS-plastic housing.
* Application : O2 monitor/dectors, Food industrial (
Refrigerator, Vegetable factory ), Bio-Technology (
Oxygen incubator, Anaerobic cultivator ), Security
system ( Air conditioner and Oxygen shortage alarm
system, Fire alarm system ), Fuel cell system.
2. SPECIFICATIONS
2-1 General Specifications
Display LCD size : 28 mm x 19 mm.
Measurement O2 ( Air oxygen )
Temperature ( Air Temp. )
Sensor Oxygen Galvanic cell type
Temperature Thermistor
1

Circuit Custom one-chip of microprocessor LSI
circuit.
Data Hold Freeze the display reading.
Sampling Time Approx. 1 second.
Power off Auto shut off saves battery life.
Operating 0 to 50 .℃
Temperature
Operating Less than 80% R.H.
Humidity
Power Supply DC 1.5 V battery ( UM4/AAA ) x 4 PCs.
Power Current Approx. DC 4.0 mA
Weight 194 g/ 0.43 LB.
Dimension 180 x 40 x 40 mm (7.1" x 1.6" x 1.6")
Accessories Instruction manual.....................
.
1 PC
Included Soft carrying case ( CA-52A )......
.
1 PC
Application * O2 monitor/dectors.
* Food industrial :
Refrigerator, Vegetable factory
* Bio-Technology :
Oxygen incubator, Anaerobic cultivator
* Security system :
Air conditioner and Oxygen shortage
alarm system, Fire alarm system
* Fuel cell system.
2

2-2 Electrical Specifications (23±5 )℃
O2 ( Air oxygen )
Range 0 to 30 %O2.
Resolution 0.1 %O2.
Accuracy ± ( 1 % reading + 0.2 % O2 ).
@ After calibration
Response time 15 seconds.≦ @ t 90
Overload 100 %O2.
protection
Environment 0.9 to 1.1 atmosphere.
pressure range
Expected life 2 years.≧
time
Alarm If the measurement Air oxygen value
< 18.0 %O2, the buzzer wll sound
for warning.
Temperature ( Air Temp. )
Range 0 to 50 ,32 to 122 .℃℃℉ ℉
Resolution 0.1 degree
Accuracy - ± 0.8 .℃℃
- ± 1.5 .℉℉
@ Above specification tests under the environment RF Field Strength less than
3 V/M & frequency less than 30 MHz only.
3

3. FRONT PANEL DESCRIPTION
Fig. 1
3-1 Oxygen/Temp. Sensor
3-2 Power Button
3-3 Hold Button
3-4 REC Button
3-5 LCD Display
3-6 Battery Compartment/Cover
4

4. MEASURING PROCEDURE
4-1 O2 ( Air oxygen )/Temp. ( Air Temp. )
measurement
1)Power on the meter by pressing the " Power Button "
( 3-2, Fig. 1 ) once,
* Press the " Power Button " once again will power off.
2)Locate the " Oxygen/Temp. Sensor " ( 3-1, Fig. 1 )
to the position that intend to make the measurement.
The upper Display ( 3-5, Fig. 1) will show the O2 ( Air
oxygen ) value in the unit of " %O2 ".
The lower Display ( 3-5, Fig. 1) will show the
Temperature ( Air Temp. ) value in the unit of " " or℃
" ".℉
O2 Buzzer warning
If the measurement value < 18.0 %O2, the
buzzer will sound for warning.
O2 Buzzer warning disable
Power off the meter, press the " REC Button "
( 3-4, Fig. 1 ) continuously then power on the
meter ( press the " Power Button " once ), the
O2 buzzer warning function will be disable.
4-2 Data hold
1)During the measurement, press the " Hold Button "
( 3-3, Fig. 1 ) momentarily to hold the measured
value. The LCD will show a " HOLD " symbol.
2)Press the" Hold Button " once again to release the
data hold function.
4-3 Data Record ( Max., Min reading )
1)The Data Record function can memorize the maximum
and minimum readings. Press the " REC Button " ( 3-4,
Fig. 1 ) once to start the Data Record function and
there will be a " REC " symbol on the display.
5

2)With the " REC " symbol on the display :
a)Press the " REC Button " ( 3-4, Fig. 1 ) once, the
" REC MAX " symbol along with the maximum value
will appear on the display.
* If intend to delete the maximum value, just press
the " Hold Button " ( 3-3, Fig. 1 ) once, then the
display will show the " REC " symbol only & execute
the memory function continuously.
b)Press the " REC Button " ( 3-4, Fig. 1 ) again, the
" REC MIN " symbol along with the minimum value
will appear on the display.
* If intend to delete the minimum value, just press
the " Hold Button " ( 3-3, Fig. 1 ) once, then
the display will show the " REC " symbol only &
execute the memory function continuously.
c)To exit the memory record function, just press the
" REC " button for 2 seconds at least. The display will
revert to the current reading.
4-4 Auto power off
1)In order to prolong the battery life, the instrument
has "Auto Power Off " function. The meter will
switch off automatically if no buttons are pressed
for around 10 minutes.
2)If intend to disable the " Auto power off " mode, then
just execute the " Data Record " function ( Refer to
chapter 4-3, page 5 ).
4-5 Set the Temp. unit ( , ) with default℃℉
1)Power OFF the meter.
2)Press the " Hold Button " ( 3-3, Fig. 1 ) continuously,
use another finger power ON the meter ( press the "
Power Button " once ), until the Temp. unit ( or )℃℉
is presented on the Display then release the " Hold
Button ", the Temp. unit will change From to ( or℃℉
to ) with default.℉℃
6

5. CALIBRATION
1)Due to the air oxygen value is 20.9 % typically, so use
the environment air oxygen value for quick & precise
calibration)
Please make calibration procedures under wide and
ventilating environment for best effect.
2)Power on the meter, Wait 3 minutes at least until the
display reading values become stable & no fluctuation.
3)Use the two fingers to press both the " Hold Button "
( 3-3, Fig. 1 ) and the " REC Button " ( 3-4, Fig. 1 ) at
the same time. Until the upper Display show the text
" CAL " ( the lower Display will show the value 20.9 ),
release the two fingers from the buttons, the text
" CAL " will flashing within several seconds, then the
Display will return to normal screen and show O2
value to " 20.9 ± 0.1 %O2 " and finish the calibration
procedures.
6. BATTERY REPLACEMENT
1)Replace the batteries when the left corner of the LCD
displays the low battery icon " ".
2)Prepare 4 fresh 1.5 V ( UM4, AAA ) batteries.
3)To change the batteries, open ( rotate clockwise direction )
the " Battery Cover " ( 3-6, Fig. 1 ).
4)Make sure the " Battery cover " (3-6, Fig 1) is secured
after changing the batteries.
71010-PO2250