Products catalog

Home/Product Catalog/HVAC control solutions for heating and ventilation/HVAC automation/Sensors and detectors/Temperature sensors and thermostats
  • New item   Temperature transducer PT100 to 4–20 mA | −100…+100 °C | 9–30 V DC | 1 DIN module | without sensor | F&F AT-3I

    Temperature transducer PT100 to 4–20 mA | −100…+100 °C | 9–30 V DC | 1 DIN module | without sensor | F&F AT-3I

    Code: AT-3I
    Inquire about this item
    Price 74.19 € VAT incl.
    ( 61.31 € VAT excl. )
    Want another price? Suggest yours!

    F&F AT-3I converts a PT100 sensor signal into 4–20 mA within −100…+100 °C and allows it to be transmitted up to 300 m. Supply 9–30 V DC, 1 DIN rail module, sensor not included.

  • Product description

    Temperature Transducer PT100 → 4–20 mA | −100…+100 °C | 9–30 V DC | 1 DIN module | without sensor | F&F AT-3I

    F&F AT-3I is a temperature transducer that converts the resistance of an external PT100 sensor into a standard 4–20 mA current signal. The measuring range is −100…+100 °C. The transducer takes 1 module (18 mm) on a 35 mm DIN rail and is supplied with 9–30 V DC. The sensor is not included – it is selected according to the location (pipe, tank, air).

    ⚠ Supply 9–30 V DC only. Do not connect the transducer directly to a 230 V AC network – it will be damaged.
    Key idea:
    Many controllers, PLCs and indicators accept 4–20 mA but not a PT100 sensor directly. AT-3I bridges the sensor and the controller: the current signal is resistant to interference and can be transmitted over a cable of up to 300 m. Temperature can be measured far from the panel without changing the controller.
    Input
    PT100
    Range
    −100…+100 °C
    Output
    4–20 mA
    Supply
    9–30 V DC

    Operating principle

    PT100 is a platinum resistance sensor with 100 Ω at 0 °C (IEC 60751); its resistance increases as temperature rises. AT-3I measures this resistance and calculates the temperature.

    The measured value in the −100…+100 °C range is converted into a 4–20 mA analogue current signal. The output is fitted with an anti-interference filter.

    A current signal depends little on cable resistance, so the output signal cable can be up to 300 m long. Pluggable 2.5 mm² terminals are used for connection.

    Why use a PT100 to 4–20 mA transducer?
    It lets you connect a PT100 sensor to any device with a 4–20 mA input – PLC, controller, indicator or recorder. The signal is transmitted over long distances without accuracy loss due to the cable.

    Technical specifications

    Product type Temperature transducer with current output
    Manufacturer / model F&F / AT-3I (MAX-AT-3I)
    Supply voltage 9–30 V DC
    Sensor type PT100 (external, not included)
    Compatible probe F&F RT56 (PT100)
    Measuring range −100…+100 °C
    Output signal 4–20 mA
    Maximum measuring error ±1.0 °C
    Processing error ±0.5 %
    Output signal cable length up to 300 m
    Power consumption 0.8 W
    Terminals Pluggable, 2.5 mm²
    Tightening torque 0.4 N·m
    Operating temperature −20…+50 °C
    Width 1 module (18 mm)
    Mounting On 35 mm DIN rail
    Degree of protection IP20

    Main functions

    • PT100 → 4–20 mA – sensor resistance converted into a standard industrial signal.
    • Range −100…+100 °C – for refrigeration, heating, ventilation and process applications.
    • Output interference filter – a more stable signal in panels with drives and contactors.
    • Signal cable up to 300 m – the controller can be far from the measuring point.
    • Supply 9–30 V DC – a standard 12 V or 24 V DC supply will do.
    • 1 DIN rail module – takes just 18 mm in the panel.
    • Pluggable terminals – easy replacement without disconnecting wires from the terminals.
    • Low consumption 0.8 W – little load on the power supply.

    How does it differ from similar products?

    Transducer with adjustable range Allows a narrower or wider measuring span to be set. AT-3I has a fixed −100…+100 °C range, so nothing needs to be configured.
    Head-mounted transmitter Installed in the sensor connection head at the process. AT-3I sits in the panel on a DIN rail, where it is easy to service.
    PT100 directly to the controller Only possible if the controller has an RTD input. With a 4–20 mA transducer any analogue current input will do, and the signal tolerates long cables better.

    Where is it used?

    • Heat substation and boiler room automation
    • Ventilation and air-conditioning systems
    • Cold rooms and refrigeration equipment
    • Temperature control of process liquids and tanks
    • Building management systems (BMS) and data logging
    • Indicators and PLCs with 4–20 mA inputs

    Use by need

    Beginner.
    Connect the PT100 sensor, the 24 V DC supply and the 4–20 mA output to an indicator or controller – no configuration needed.
    Experienced installer.
    Use a shielded twisted pair for the signal cable and route it apart from power cables – the 300 m distance can be used without interference.
    Power engineer / designer.
    Assess the total error: sensor class plus transducer error (±1.0 °C, processing ±0.5 %) and controller input accuracy.

    Practical use

    A heat substation controller has only 4–20 mA inputs, and the return water temperature must be measured at a manifold 120 m away. A PT100 sensor in a thermowell is installed at the manifold, and the AT-3I with a 24 V DC power supply in the panel. The controller receives a stable current signal that is insensitive to cable length.

    Pros / advantages

    • Ready to use – no configuration
    • Standard 4–20 mA output
    • Signal transmission up to 300 m
    • Wide supply range 9–30 V DC
    • Narrow housing – 1 module
    • Output interference filter
    • Made by a European manufacturer (F&F, Poland)

    Cons / limitations

    • Fixed range −100…+100 °C – not suitable for higher temperatures
    • Sensor not included
    • Requires a separate DC power supply
    • IP20 – panel mounting only

    Safety and installation notes

    • ⚡ If the panel contains 230 V AC circuits, installation by a qualified electrician with the supply disconnected.
    • Supply the transducer with 9–30 V DC only – 230 V AC will destroy it.
    • Route sensor and signal cables separately from power cables; a shielded cable is recommended.
    • Tighten terminals to 0.4 N·m, wires up to 2.5 mm².
    • Observe the operating temperature of −20…+50 °C in the panel.
    • Check the sensor wiring diagram in the manufacturer's instructions.

    Quick selection guide

    PT100
    −100…+100 °C
    4–20 mA
    9–30 V DC
    Suitable when you need:
    • to connect a PT100 sensor to a 4–20 mA input
    • to transmit a temperature signal over a long distance
    • to measure temperature within −100…+100 °C
    • a compact DIN rail solution
    Check before choosing:
    • that the measured temperature does not exceed +100 °C
    • that you have a PT100 sensor (not PT1000, NTC or KTY)
    • that a 9–30 V DC power supply is available
    • the controller input type – 4–20 mA
    Important reminder: AT-3I works only with a PT100 sensor and only in the −100…+100 °C range. It will not work with PT1000, NTC or a thermocouple.
    ☝ Elsprendimai.eu recommends:

    FAQ

    Is AT-3I sold with a sensor?
    No. The transducer is supplied without a sensor – a PT100 sensor must be purchased separately for the measuring point.
    Can a PT1000 sensor be connected?
    No. AT-3I is designed for a PT100 sensor; with a PT1000 the measurement will be wrong.
    How long can the signal cable be?
    The manufacturer states an output signal cable length of up to 300 m.
    What power supply is suitable?
    Any regulated 9–30 V DC supply; in panels a 24 V DC DIN rail power supply is most common.
    What is the transducer error?
    Maximum measuring error is ±1.0 °C, processing error ±0.5 %. The sensor accuracy class adds to this.
    Can temperatures above +100 °C be measured?
    No, the AT-3I range is −100…+100 °C. Higher temperatures require a transducer with a wider range.

    Sources: F&F Filipowski (Poland) AT-3I product page and datasheet. Checked 2026-10-18.

    F&F AT-3I PT100 to 4–20 mA transducer

    F&F AT-3I converts a PT100 sensor signal into 4–20 mA within −100…+100 °C. Supply 9–30 V DC, 1 DIN rail module, signal cable up to 300 m – a practical way to connect PT100 to PLCs, controllers and indicators.

    Illustrative image may have been created using AI. The appearance of the product may differ slightly from the image shown. Please refer to the technical specification.

  • Alternative products

    Duct temperature sensor | NTC 10 kΩ | passive resistive | for air ducts Duct temperature sensor | NTC 10 kΩ | passive resistive | for air ducts New item  
    Duct temperature sensor | NTC 10 kΩ | passive resistive | for air ducts
    Code: NTC10 kOm
    Price 24.20 € VAT incl.
    ( 20.00 € VAT excl. )
    Add to cart 
    Duct temperature sensor | Ni1000 | 1000 Ω at 0 °C | for ducts Duct temperature sensor | Ni1000 | 1000 Ω at 0 °C | for ducts New item  
    Duct temperature sensor | Ni1000 | 1000 Ω at 0 °C | for ducts
    Code: Ni1000
    Price 24.20 € VAT incl.
    ( 20.00 € VAT excl. )
    Add to cart 
    Duct temperature sensor | NTC 1.8 kΩ | passive resistive | for air ducts New item  
    Duct temperature sensor | NTC 1.8 kΩ | passive resistive | for air ducts
    Code: NTC 1.8 kOm
    Price 24.20 € VAT incl.
    ( 20.00 € VAT excl. )
    Add to cart 
    Duct temperature sensor | NTC 20 kΩ | passive resistive | for air ducts Duct temperature sensor | NTC 20 kΩ | passive resistive | for air ducts New item  
    Duct temperature sensor | NTC 20 kΩ | passive resistive | for air ducts
    Code: NTC20 kOm
    Price 24.20 € VAT incl.
    ( 20.00 € VAT excl. )
    Add to cart 

  • Subscribtion to new arrivals

    privacy policy

    Information