Transmitter LKM281 for thermocouples
The LKM281 is a digital, programmable transmitter with galvanic isolation between input and output for mounting on the standard rail. It can be set for different thermocouples according to DIN EN 60584 and DIN 43710. It converts the temperature-dependent thermoelectric voltage of the sensor by means of 3-wire technology into a standard signal of 4...20mA, 0...20mA or inverse. The temperature compensation takes place in the transmitter itself.
With the increased interference and shock resistance, a wide supply voltage range and the slim design of 6mm, this transmitter is particularly well suited for use in motor vehicles.
It is supplied in a customer-specific configuration. Subsequent changes to the sensor and measuring range can be made via the mini-USB interface on a PC. The required program is available free of charge in the "Downloads" tab.
A zero point controller can be used to make a small correction on site. Additionally, an offset can be set via software.
The selection menu is available for configuration.
When entering your individual measuring range, please note the measuring range of the selected sensor. This can be found in the technical data. The minimum span is 200°C.
| Type | Measurement range in °C |
|---|---|
| B | 300 – 1820 |
| C | 0 – 2315 |
| E | -150 – 950 |
| J | -200 – 1200 |
| K | -200 – 1370 |
| L | -200 – 900 |
| N | -200 – 1300 |
| R | -50 – 1760 |
| S | -50 – 1760 |
| T | -250 – 400 |
| U | -250 – 600 |
| Feature | Value | Remark |
|---|---|---|
| Zero | Entire measurement range | depending on thermocouple |
| Span | > 50 K | |
| Linearity error | < 0,3 K | |
| Measurement error | < 0,2 % | |
| Reference-junction error | <±0,5 °C | |
| Supply voltage | 8 – 35 VDC | reverse-polarity protected |
| Max. current consumption | 23 mA | at 24 VDC |
| Isolation | > 2.5 kV | |
| Output | 4 – 20 mA / 20 – 4 mA / 0 – 20 mA / 20 – 0 mA, 3-L | |
| Sensor break | > 20 mA | typically 21 mA |
| Short-circuit | current value corresponding to room temperature | |
| Response time | < 0,5 s | |
| Temperature coefficient | < 100 ppm/K | |
| Operating temperature range | -40 – 85 °C | |
| Humidity | < 95 % | |
| Mounting | 35 mm DIN rail | |
| Material | Polyester | |
| Dimensions | 100 × 6 × 93 mm | H x W x D |
| Terminal type | Screw terminals | Spring-clamp terminals possible |
| Terminal cross-section | 0.2 – 2.5 mm² | |
| Weight | approx. 54 g | |
| Vibration | 147 – 500 Hz / 300 ms² / 500 Hz – 2 kHz / 200 ms² | |
| EMC | EN 61326-1 EN 61326-2-3 |
Emission and immunity |
Documents
| Document | Format | Language(s) |
|---|---|---|
| Datasheet – LKM281 Technical Specification |
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| Operating Instructions – LKM281 Installation and operating manual |
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Software
| Program / Package | Format | Language(s) |
|---|---|---|
| Service Program – LKM281 for Windows-PCs Parameterization Software |
ZIP |  |
| Program – AnalogToTemperatur Conversion of analog output values (mA or V) to temperature |
ZIP | |
| Driver (ftdichip.com) USB driver |
Web | |