JETI model MT125, MT300 User Manual

MT125 & MT300 Sensor EX

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Designation of MT Sensors are temperature measurements of devices like motors, controllers,
batteries and other model accessories. Presentation of the measured data is realized by the JETIBOX
terminal and the wireless information transfer is ensued with aid of the DUPLEX 2,4GHz system.
The Duplex System takes advantage of the 2,4GHz-Band for communication which allows not only
the transfer of remote control data to the model, but also in the opposite direction to the transmitter. The
telemetric data measured during operation are transmitted in real time and the actual state of the data can
be depicted on the JETIBOX LCD-display. The MT unit records minimum and maximum temperatures of
the individual sensors and delivers besides that their actual values.
The JETIBOX terminal takes care of parameter adjustments as well as of indications of measured data.
The MT device consists of two parts. In the first instance of the MT module itself, which is recording the
data measured by temperature sensors connected to the MT module, which on the other hand can be
connected to the JETIBOX, to a receiver or to an Expander of the DUPLEX system. Keep an eye on the
temperatures of the module and sensors in order not to expose them to temperatures higher than allowable
– see technical data table.
The MT module allows triggering of acoustic alerts by the individual sensors. These alerts can report
of temparature limit violations by too high or too low temperatures exceeding adjusted limits. The
acoustic signal is generated by the transmitter module DUPLEX Tx which contains a small siren. The
signals are differentiated by Morse codes in order to be able to distinguish between the individual types of
alerts referring to individual sensors. The acoustic signalling of parameter violations will be generated
even if there is no JETIBOX available. With a connected JETIBOX there will be an indication on its
display showing which parameter has been violated. If several parameters have been violated at the same
time the alert sounds change consecutively as well as the indications in the JETIBOX LCD-display.

Technical Data

MT125

MT300

Dimensions

19 x 14 x 4 mm

19 x 14 x 4 mm

Weight (without cables)

10 g (4 g)

6 g ( 3 g)

Number of Temprature Sensors

2

2

Temperature Sensor Range

- 55°C +125°C

- 40°C +300°C

Measuring Accuracy

0,5 °C

5 °C

MT-Module Operation Temperature

- 10°C to + 85° C

- 10°C to + 85° C

Supply Voltage

3,5 – 8,4V

3,5 – 8,4V

MT-Module & Sensor intrinsic consumption

7 mA

20 mA

Connection of MT-Sensors

In the MT125 Module you will find two inputs for the connection of temperature sensors coded A
and B. Connect the sensors to these inputs while paying attention to polarity (red sensor wire to + and the
black one to - ). Constituent parts of the MT300 sensor are two sensors which comprise a loop of heat
resistant conductor in the central part. A silicon tube sliding over the loop serves for fastening purposes.

Fastening of the sensors

Place the MT-Module as far away as possible from
heat sources in order not to exceed the allowed
maximum temperature.
Sensors of the MT125 Module are able to measure

temperatures up to 125°C. Fasten the sensor to the

measured object as secure and tight as possible in
order to prevent contact losses and herewith falsify
measurement results. Choose a fastening method
which corresponds to the assumed maximum
temperature of the measured object. For low
temperatures you may choose glue or shrink tubing
(batteries, controllers etc.). In case of higher
temperatures fasten the sensors by means of the
enclosed plastic tape.

MT125 & MT300 Sensor EX

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Sensors of the MT300 Module can be used for higher temperatures (engine cylinders, engine exhausts
etc.). The sensors are adapted to this purpose and comprise a loop of heat resistant conductor in the
middle. Before tightening moisten the silicon tube with alcohol or white spirit in order to improve its
sliding ability on the cables. Put the measuring object, for instance an engine cylinder, through the loop
and tighten the loop strongly by means of the silicon tube in order to obtain a tight contact between the
loop and the measuring object (for instance with cooling fins of an engine cylinder). After evaporation of
the alcohol the silicon tube will firmly hold the loop tight. In order not to damage the sensor the dia. of
the loop should not be smaller than 20 mm.

Parameter adjustment of MT-Modules

Parameter adjustment a data readout is accomplished by the JETIBOX terminal. After connection to the
MT-Sensor there appears an identification of the sensor and in the second line the actually measured
temperature data of both sensors. By long pushing down button R (right) a fast deletion of all measured
parameters can be triggered. Fast deletion is indicated in the first line of the display by an asterix „*“.
By pushing button D (downward arrow) of the JETIBOX you will enter the MT-Module menu.

Menu of the MT-Module:
MT125 MENU: ACTUAL VALUE – select presentation of actual measured data by pressing button D

(down arrow)

Actual Temp. A – presents the actual temperature of sensor A
Actual Temp. B – presents the actual temperature of sensor B

MT125 MENU: MIN / MAX – push button D (down arrow) in order to select the recorded extreme
values which occured during measurements on both sensors.
Temp. A MIN / MAX – represents the minimum and maximum temperature value which has been
recorded by sensor A during all measurements.
Temp. B MIN / MAX – represents the minimum and maximum temperature value which has been
recorded by sensor B during all measurements.

Records of all extremes can be deleted in the menu Setting - Erase Data. If you don´t delete all data
records manually, the MT-Module will record the maximum and minimum sensor temperatures whether
it has been in the meantime disconnected of the voltage supply or not, i. e. the presented data can concern
preceding operations.

MT125 MENU: Setting – by pushing button D (down arrow) the basic MT-Module adjustment will be
selected.
Erase Data – pushing buttons R and L (right and left arrows) simultaneously will delete all records of
measured parameters (minimum and maximum temperature values of sensors A and B).
Beep Temp. A – adjustment of a Morsealphabet character which will announce violation of the set alert
temperature of sensor A by an acoustic signal of the DUPLEX Tx transmitter module.
Beep Temp. B – adjustment of a Morsealphabet character which will announce violation of the set alert
temperature of sensor B by an acoustic signal of the DUPLEX Tx transmitter module.

MT125 MENU: ALARMS – by pushing button D (downward arrow) you will enter the adjustment
modes of particular alerts. If violation of a set parameter occurs the indication of the JETIBOX LC
display will show in the second line of the basic menu the original indication as well as the particular alert
indication alternately and the siren of the transmitter module will emit alert signals. The first tone is a
reference signal and the second tone is the corresponding Morse signal of the particular alert. There will
be no particular signal emitted if the alert is in OFF position.
Temp. High A – signal adjustment for high temperatures, if the measured temperature exceeds the set
value alert of sensor A will be activated.
Temp. Low A – signal adjustment for low temperatures, if the measured temperature is below the set value
alert of sensor A will be activated.
Temp. High B – signal adjustment for high temperatures, if the measured temperature exceeds the set
value alert of sensor B will be activated.