Our all-digital RS485 Modbus line of combination sensors are an accurate industry standard.  Depending on your requirements, you can select sensors with many different specifications from our wide range of products.

Application

IMT Solar offers a complete line of temperature sensors for use in long term performance monitoring of solar PV modules and systems.  We offer both a back of module temperature sensor and an ambient temperature sensor.  Both models are available in RS485 Modbus output.

Function

Our sensors use a high-quality monocrystalline solar cell connected to a high accuracy shunt.  The low shunt resistance causes the cell to operate close to the short-circuit point.

To compensate for any possible measurement shifts caused by the temperature co-efficient relationship with the Isc., all of our silicon sensors with the part number extension of “TC” employ active temperature compensation.  The compensation is realized by using a specific temperature sensor laminated to the rear side of the solar cell.  One of the key elements of the electronic compensation circuit design is very low power consumption.

All sensors are calibrated in simulated sunlight against a reference cell of the same type.  The reference cell calibration is periodically verified using a reference cell calibrated by Fraunhofer ISE, Freiburg.

Mechanical Construction

Our sensors are built using a powder-coated aluminum case sealed to IP 65.  The solar cell is embedded in Ethylen-Vinyl-Acetate (EVA) between glass and Tedlar™, then the laminated cell is integrated into the powder-coated aluminum case.  This configuration of the sensor is comparable to that of a standard PV module making the sensor an ideal choice for irradiance monitoring of commercial PV installations.

The electrical connection for the sensor is realized by an integrated cable or with an IP67 rated connector.  A cable length of 3 meters is standard for most of our sensors.

Cell Temperature

All of our digital RS485 Modbus sensors allow you to read the back of internal cell temperature. This is loosely correlated with, though not a replacement for, a back of module temperature reading.

Solar Irradiance Specifications

General Information

  • Solar cell: Monocrystalline Silicon (50 mm x 33 mm)
  • Current shunt: 0.1 O (TC = 20 ppm / K) for 1 V and 20 mA output sensors 0.12 O (TC = 20 ppm / K) for 10 V output sensors, 0.1 O (TC = 30 ppm / K) for digital output sensors
  • Operating temperature: – 35 °C to 80 °C
  • Electrical connection via shielded cable, length 3 m standard, or IP 67 rated connector
  • Case, protection mode: Powder-coated aluminum, IP 65
  • Dimension,Weight: 155mm x 85mm x39mm, 400g

Accuracy

  • Irradiance: ±0.4W/m2 ± 1.6% from value; with temperature compensation, vertical light beam and AM 1.5
  • Temperature: 1.0K uncertainty

 Available Sensor Types:

  • Si-RS485TC-2T-MB: Plane of array irradiance sensor with integrated ambient temperature sensor
  • Si-RS485TC-T-Tm-MB: Plane of array irradiance sensor with integrated back of module temperature sensor
  • Si-RS485TC-2T-v-MB: Plane of array irradiance sensor with 1 auxiliary port for a wind speed sensor and 1 auxiliary port for a temperature sensor
  • Si-RS485TC-3T-MB: Plane of array irradiance sensor with 2 auxiliary ports for temperature sensors
  • Vwind-Si: Auxiliary wind speed sensor compatible with Si-RS485TC-2T-v-MB
  • Tmodul-Si: Auxiliary back of module temperature sensor compatible with Si-RS485TC-2T-v-MB and Si-RS485TC-3T-MB
  • Tamb-Si:  Auxiliary ambient temperature sensor compatible with Si-RS485TC-2T-v-MB and Si-RS485TC-3T-MB
  • Shield-Tamb-Si: Optional weather shield compatible with Tamb-Si, Si-RS485TC-2T-MB, or Ta-ext-RS485-MB ambient temperature sensors