Description
The EKMF does not transmit, it switches. It takes one Pt100 in two-wire connection over −50 to 500 °C or a thermocouple of type K over −50 to 1200 °C and drives a relay contact — normally open or normally closed, selected by the jumper J1 in the device. That makes it an inexpensive limit switch or a two-point controller, a replacement for a thermostat or a bimetal switch. The switching point is set in two ways: over HART with the graphical tool, together with hysteresis, switching delay and damping, or without any tool by holding a magnet to the marked spot while the sensor sees the wanted temperature — the red LED blinks three times when the new value has been taken. In normal operation that LED shows the state of the contact. The case is the same round PA66 housing as the transmitters of this family, Ø 45 × 23 mm and IP20.
Measurement and switching
- Pt100, 2-wire, −50 … 500 °C
- Thermocouple type K, −50 … 1200 °C
- Cold junction compensated internally
- Relay contact NO or NC, jumper J1
- 1 A at 30 V DC · 0.3 A at 125 V AC
- Accuracy ± 0.5 °C, measuring rate 10 per s
- Hysteresis and delay set over HART
- Switching point also set by magnet
Device and connection
- Supply 24 V DC ± 5 V
- Reverse polarity protection
- Case synthetics PA66, black
- Dimensions Ø 45 × 23 mm, approx. 35 g
- Terminal screws, conductor to 1 mm²
- Protection class IP20
- Operating temperature −20 … +70 °C
- EN 61000-6-4 and EN 61000-6-2
All technical data, dimensions and available versions are listed in the datasheet for download.