4.11 Digital Output.............................................. 7
5
7
MARTEL 303
I. Introduction:
This instrument is a digital thermometer for use with
any K-type and J-type thermocouple as temperature
sensor.
Temperature indication follows National Bureau of
Standards and IEC584 temperature/voltage table for
K-type and J-type thermocouples.
II. Specifications:
Numerical Display:
4 digital liquid crystal display
Measurement Range:
K-Type -200℃ ~ 1370℃
-328℉ ~ 2498℉
J-Type
-200℃ ~ 760℃
Resolution:
Maximum Voltage at Thermocouple Input:
Environmental:
R Operating Temperature and Humidity:
0°C ~50°C (32°F ~ 122°F); 0~80% RH
R Storage Temperature and Humidity:
-10°C to 60°C (14°F ~ 140°F); 0~80% RH
R Altitude up to 2000 meters.
-328℉ ~ 1400℉
K-Type:
-200°C~ 800°C, 0.1°C; 800°C ~1370°C, 1°C
-328°F~ 1000°F, 0.1°F; else 1°F
J-Type:
-200°C~ 600°C, 0.1°C; 600°C ~760°C, 1°C
-328°F~ 1000°F, 0.1°F; else 1°F
60V DC, or 24Vrms AC
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MARTEL 303
Accuracy: at ( 23 ± 5°C )
Range Accuracy
K-Type -200°C ~ 1370°C ±(0.1% reading + 0.7°C)
J-Type -200°C ~ 760°C ±(0.1% reading + 0.7°C)
K-Type -328°F ~ 2498°F ±(0.1% reading + 1.4°F)
J-Type -328°F ~ 1400°F ±(0.1% reading + 1.4°F)
For T1-T2 Measurement, the accuracy is
±( 0.2% T1-T2 reading + 1.7°C) or
±( 0.2% T1-T2 reading + 3.4°F)
Temperature Coefficient:
For ambient temperatures from 0°C ~ 18°C and
28°C ~ 50°C, for each °C ambient below 18°C or
above 28°C add the following tolerance into the
accuracy spec.
0.01% of reading + 0.03°C ( 0.01% of reading + 0.06°F )
Note:
The basic accuracy Specification does not include
the error of the probe. Please refer to the probe
accuracy specification for additional details.
Sample Rate: 2.5 times per second
Dimension: 7.36”x2.56”x1.2” (184x64x30 mm)
Weight: 7.4oz. Approx. (210g)
Accessories:
Software Package (Program, RS232 Connection
Cable), AC Adapter.
Power requirement:
9 Volt Battery, NEDA 1604 or JIS 006P or IEC6F22
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MARTEL 303
Battery Life:
Approx. 100hrs with alkaline battery
AC Adapter:
9V
DC ±15% 100mA
III. Symbol Definition and Button
Location:
Main Display Second Display
:This indicates that the minus temperature is
-
°C °F
:Centigrade and Fahrenheit indication.
K J
:Thermocouple Type Indication
HOLD :This indicates that the display data is being held.
MAX :The Maximum value is now being displayed
MIN :The Minimum value is now being displayed
AVG :The Average value is now being displayed.
△REL
sensed.
:The reading is now under Relative Mode.
:The Battery is not sufficient for proper operation.
3
1
T1 K J type temperature sensor connector
○
2
T2 K J type temperature sensor connector
○
3
LCD display
○
4
ON/OFF button
○
5
HOLD button
○
6
T1,T2,T1-T2 control button
○
7
Relative readout button
○
8
MAX MIN Average control button
○
9
°C, °F control button
○
10
Digital output connector
○
12
AC power adapter connector
○
13
Tripod connector
○
14
Battery cabinet cover
○
MARTEL 303
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MARTEL 303
IV. Operation Instructions:
4.1 Power-Up
Press the ○
4.2 Connecting the Thermocouples
Plug the thermocouple into the input connectors.
4.3 Selecting the Temperature Scale
When the meter is first powered on, the default scale
is set at Celsius (°C). Change it to Fahrenheit (°F) by
pressing “ °C/°F ” button, Press it again to change
back to Celsius.
4.4 Selecting the Thermocouple Type
By default, when the meter is powered on, it defaults
to a K-Type, To change to a J-Type, press and hold
the “°C/°F” button while turning on the meter.
4.5 Data-Hold Operation
Hold the present reading and keep it on the display
by pressing the “
operation by pressing the “
When the meter is under Data Hold operation, the
“△REL”, and “ °C/°F ” buttons are disabled.
4.6 T1,T2,T1-T2 Display Control:
Select T1, T2 , or T1-T2 to show on the main display
by pressing the button. When T1 or T2 is
selected to show on the main display, the other
temperature will be shown on the secondary display.
Selecting T1-T2 will display the difference between
the T1 and T2 inputs.
4.7 Relative Operation for Main Display:
When the “△REL” button is pressed, the meter will
I
key to turn the thermometer ON or OFF.
HOLD” button. Release the data-hold
HOLD
” button again.
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MARTEL 303
memorizethe presentreading and will then
the difference between the new reading and
display
the memorized data. Press the “△REL” button again
to exit the Relative operation.
4.8 MAX/MIN/AVG Operation for Main Display:
When the button is pressed, the meter will
enter the MAX/MIN mode. In this mode, the
maximum value, minimum value, and average value
of latest four (4) data samples is kept in the memory
simultaneously, and updated with every new data
sample.
When the MAX symbol is displayed, the Maximum is
shown on the display.
Press again, the MIN symbol will show on the
display along with the minimum reading.
Press again, the AVG symbol will show on the
display along with the average reading.
Press again, MAX, MIN and AVG will blink
together. This means that all data is updated in the
memory and the reading is the present temperature.
Press to circulate the display mode among
these options.
When the meter is in the mode, “△REL” and
°C/°F ” are disabled.
“
To exit the MAX/MIN mode, press and hold
for two seconds.
4.9 Auto Power Off:
By default, when the meter is powered on, it is under
auto power off mode. The meter will power itself off
after 30 minutes if there are no key operations or
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MARTEL 303
RS232 communication.To disable the auto power off
HOLD
feature, press the “
meter. Two successive beeps indicates the auto
power off feature is disabled.
4.10 Low Battery Condition
When the battery voltage falls below that required for
proper operation, the symbol will show on the
display. Replace the battery.
4.11 Digital Output:
The Digital Output is a 9600bps N 81 serial interface.
The RX is a 5V normal high input port.
The TX is a 5V normal high output port.
The commands for the Digital Output are listed below.
RS232 command Function Remarks
K(ASC 4BH) Ask for model No. Send 4 bytes
H(ASC 48H) Hold button
T(ASC 54H) TIMER button
Return 4 bytes. For example, when sends command
"K" to meter, it will return "3","0","3", ASCII(13) .
(0x13) represent T1,- 199.9°C, The total byte
number should be 7+1+7+1+5+chr(13)=22Bytes
” button while turning on the
RX
TX
GND
Send encoded 8
byte
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MARTEL 303
•Command T:
Equivalent to pushing the HOLD button.
•Command M:
Equivalent to pushing the HOLD and AVG/MAX/
MIN buttons and no message is returned.
•Command R:
Equivalent to pushing the REL button and no
message is returned.
•Command C:
Equivalent to pushing the ℃/℉ button and no
message is returned.
•Command A:
nd
BYTE:
1
The first byte is the start byte , its value is 2.
bit3:1Ɩ0ƖK TYPE 1ƖJ TYPE
bit4:1ƖREL
bit5:1- HOLD 0Ɩnot HOLD
bit6:1ƖLOW BATTERY 0ƖBATTERY NORMAL
bit7:1Ɩ℃ 0Ɩ℉
"MAX""AVG""MIN" will flash.
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MARTEL 303
3nd BYTE:
bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
point minus OL point minus OL
bit0:1Ɩmain window value is OL 0Ɩnot OL
bit1:1Ɩ main window value is minus, 0Ɩ main window
value is plus.
th
bit2:1Ɩ4
bit3:1Ɩsub window value is OL 0Ɩnot OL
bit4:1Ɩsub window value is minus, 0Ɩsub window value
bit5:1Ɩ6
bit7 bit6:
4
5
6
7
8
byte and 5th byte represent #### 0Ɩ4th byte
th
and 5
byte represent ###.#
is plus.
th
byte and 7th byte represent #### 0Ɩ6th byte
th
and 7
byte represent ###.#
00ƖMain window is T1-T2,sub window is T1
01ƖMain window is T1-T2, sub window is T2
10ƖMain window is T1, sub window is T2
11ƖMain window is T2, sub window is T1
th
BYTE: first two BCD code of main window value.
th
BYTE: last two BCD code of main window value
th
BYTE: first two BCD code of sub window value.
th
BYTE: last two BCD code of sub window value.
th
BYTE: The last byte is the end byte , its value is 3,
first and last byte are used to check frame
error.