LF-TD 180 air humidity and temperature transmitter with a remote sensor head

Air humidity measurement in processes up to 180 °C

The LF-TD 180 is a relative humidity and temperature transmitter with a remote sensor head, made for the hottest processes in the LF-TD series. The head works over a range of -40 to +180 °C, so the device measures where ordinary humidity sensors no longer reach: in high-temperature drying kilns, ripening chambers, process flue ducts and heat treatment lines.

Typical branches are laboratory, air-conditioning and drying technology, the timber, food and feed industries, construction, printing and papermaking, agriculture, biotechnology and the pharmaceutical industry.

A head on a cable keeps the electronics out of the heat

The stainless steel sensor head, Ø 12 x 100 mm, is joined to the electronics housing by a cable 1 metre long. Only the head itself stays in the hot zone, while the electronics can hang somewhere cooler - its permitted operating temperature is -20 to +85 °C. The sintered stainless steel sensor cap belongs to the scope of delivery and withstands dust and demanding conditions.

The 4-20 mA outputs cover the whole temperature range

Humidity leaves the device as a 4-20 mA signal scaled 0 to 100 %, temperature as a second 4-20 mA signal scaled -40 to +180 °C. Both signals are accepted by any PLC, data logger and analogue input module. The supply is 12 to 29 VDC, the current consumption about 18 mA without interfaces and display.

Profinet, Ethernet, USB and RS232 to choose from

The LF-TD 180 is the only transmitter of the series for which the manufacturer offers a Profinet interface as an accessory (art. no. 12809). Besides it there are the Ethernet (art. no. 13738), USB (art. no. 12808) and RS232 (art. no. 12807) interfaces and the display with a keypad (art. no. 13731), which shows the current values on the device itself.

Calibration at six humidity points

Every LF-TD transmitter is calibrated at the factory at six humidity points. The calibration accuracy is ±2 % over the range of 10 to 90 % relative humidity and ±0.3 °C over +10 to +60 °C. A factory calibration certificate with an adjustment report is supplied on request (art. no. 10403).

Advantages The remote head on a one metre cable is the key feature here: only the sensor stays in the duct, while the electronics hang in a place no hotter than +85 °C. The capacitive humidity sensor keeps its accuracy for years, withstands the usual contamination and contact with many chemicals, and settles quickly after a change of conditions. sensor head working over -40 to +180 °C electronics kept away from the heat, joined to the head by a 1 m cable sintered stainless steel sensor cap in the scope of delivery 4-20 mA outputs for humidity and temperature factory calibration at six humidity points Profinet, Ethernet, USB or RS232 interface to choose from

Technical data

Technical drawing

Scope of delivery

LF-TD 180 with a 1.9 m connecting cable and a moulded 5-pin sensor plug.

Extended accessories

• Art. no. 12809 - Profinet interface for the LF-TD 180
• Art. no. 13738 - Ethernet interface for the LF-TD
• Art. no. 12808 - USB interface for the LF-TD
• Art. no. 12807 - RS232 interface for the LF-TD
• Art. no. 13731 - display with a keypad for the LF-TD
• Art. no. 13612 - angle bracket for the LF-TD
• Art. no. 12456 - drip guard for LF-TD transmitters
• Art. no. 10249 - spare sintered stainless steel sensor cap with a sintered filter
• Art. no. 10006 - calibration device for tube probes
• Art. no. 10352 - certified calibration ampoules, set of 5 at 50 % relative humidity
• Art. no. 10005 - certified calibration ampoules, set of 5: 2 × 35 %, 1 × 50 %, 2 × 80 % relative humidity
• Art. no. 10403 - factory calibration certificate with an adjustment report
• Art. no. 14711 - HumiSenseWare LF-TD, standard Live Trend licence - requires one of the interfaces: RS232 (art. no. 12807), USB (art. no. 12808) or Ethernet (art. no. 13738)
• Art. no. 14712 - HumiSenseWare LF-TD, data management and logging option
• Art. no. 14713 - HumiSenseWare, integration package for 3 additional sensors
• Art. no. 12011 - special version, flat rate to order, regardless of the quantity ordered

For similar applications we also recommend the LF-TD 150 with a smaller temperature range, up to 150 °C.