Temperature sensor Convertor for Photovoltaics – Temmeter 485

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Temperature sensor Convertor for Photovolatics – Temmeter 485

Temmeter-485 (TM3-485 PRO ® & TM4-485) are 2 converters from temperature sensor to RS-485 Modbus output.

Temmeter-485  is a high resistance temperature sensor convertor for photovolatic modules (solar panel), based on a PT100 temperature sensor.

Both converters are a good complement as where thermopile pyranometers are used; They do not have a socket for the module’s temperature sensors, so they are a perfect complement as resistive temperature sensor convertor for those who use a thermopile pyranometer.

Note: Solar modules exposed to high temperature produce less power than same module at 25°C. Correct Performance Ratio (P/R) calculation requires the correct formula. In Southern Europe, PV module temperatures can reach 85°C during the Summer; in those cases the losses of output power are lower of about 25%.

Soluzione Solare temperature sensor convertors are designed for outdoor use and rapid response to temperature variations (from several milliseconds to a few seconds) in order to guarantee precise Performance Ratio calculations.

Key features

  • TM4-485  differs from the TM3-485 model for the accuracy.
  • TM3-485 convert values read from any PT 100/PT1000 to RS485 Modbus through a dedicated 16 bit converter and precision is ± 0.2° C.
  • TM4-485 convert values read from a Silicon sensor encapsuled and distributed by us to RS485 modbus. Precision is ± 2.2° C.

Both models have 2 input channel for temperature measurements. Those 2 channels can be used for 2 points of module temperature or 1 module temperature and 1 ambient temperature.

Note: For identification of the probes TM4-485 is labelled with LM61 and TM3-485 is labelled with PT100. 

            If the connection is interchanged the temperature sensor convertor will not function.


  • Faster response to changes in temperature (< 5 seconds for increasing temperature; < 25 seconds for decreasing temperature);
  • Strong adhesion to surfaces with low surface tension such as Tedlar;
  • Measurement precision above the required standards of a PT100 class A sensor;
  • Shielded cable.


NAME TM 4-485 TM 3-485
Convertor from our Silicon Temp.Sensor to RS485 Convertor from any PTC to RS485
Reference standard IEC 60751
The converter is compatible with Smartlogger 3000, Sungrow Ermes, Higeco, Envolve and many others.
Measured Value Sensor 1 -30 ÷ +85 °C toll. ± 3 °C Sensor 1 -40 ÷ +110 °C toll. ± 0.2 °C
Sensor 2 -30 ÷ +85 °C toll. ± 3 °C Sensor 2 -30 ÷ +110 °C toll. ± 0.2 °C
Temperature Sensor Silicon Sensor TM4 resolution Any PT100 or PT1000 at 2-3-4 wires
Precision of the T.sensor ± 2.2ºC Depending by the PTC. With TM3 prec.± 0.15ºC
Precision of converter 0.1° C
Precision Overall ± 2.2ºC ± 0.2ºC
Calibration Each TM4 is made by a T.I, Instrument sensor factory calibrated with 2 reference points using precision reference resistances.
Output Serial: RS485, standard Modbus RTU protocol.
Distance-Covered (signal): atleast 600 m
Non-linearity ≤0.3%
Supply Voltage 8 – 30 V dc consumption < 0.06 A
Protected against reverse polarity and overvoltage
Consumption (@ 12V) 0.1 W
Encapsulation Resin conformal coating
Casing IP67 – Coated grey Aluminium
Connector INPUT: M 12 – 8 Pin FEMALE
Dimensions 97x64x34 mm
Operating temperature -40 ÷ 125 °C toll. ± 0.2° C
Box Working temperature (-30 ÷ +85 °C)
Operating humidity 0 ÷ 95% RH
Weight 200 gr

** when ordering, specify the version


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