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Transmitters for weather / wind speed and direction

TMET Transmitter with wired sockets for use with the WXT520 Vaisala weather or WMT52 Vaisala wind speed sensor. Also inputs for 1 x thermistor temperature sensor and 1 x solarimeter input (Kipp and Zonen CMP3 or Skye SKS1110). The Vaisala WXT520 weather sensor supplies the following parameters:
  • Wind speed
  • Wind direction
  • Precipitation
  • Barometric pressure
  • Air temperature
  • Relative Humidity
The TMET and the Vaisala weather sensors are both low power devices, allowing the system to be powered by any of the following:
  • Solar power
  • AC power supply
  • External 12V battery


WBT The TMET is rated for indoor use only. If to be used outdoors, the TMET must be housed in a secondary enclosure. The outdoor unit type WBT is available for this purpose. The WBT is intended for mounting on a 25mm lightweight aluminium pole.

Supplied with key-lock door and galvanised clamp for use on the 25mm dia pole. (The pole is not supplied).

Dimensions: 200 x 300 x 132mm
Vaisala WXT520 Vaisala WXT520 Weather sensor.

The WXT520 supplied by Eltek is preconfigured and includes a 26.7mm or 30mm diameter pole top adaptor and 3m connecting lead. The TMET powers the WXT520.
(TMET cannot provide wind gust data.)
Vaisala WMT52 Vaisala WMT52 Wind sensor.

The WMT52 supplied by Eltek is preconfigured and includes a 26.7mm or 30mm diameter pole top adaptor and 3m connecting lead. The TMET powers the WMT52.
(TMET cannot provide wind gust data.)
CMP3 Kipp and Zonen CMP3 sunshine pyranometer. A mounting bracket/base may be required. (e.g PyroBkt below). The CMP3 does not require power.
(TMET cannot provide sunshine hours.)
Skye SKS1110 Skye SKS1110 sunshine pyranometer. SKM221 levelling unit and SKM226 mounting bracket may be required (see image to the right). The SKS1110 does not require power.
(TMET cannot provide sunshine hours.)
SP-TMET2 10W solar panel supplied with 25mm dia pole mounting bracket and lead. Charge rate is 1A max.
The bracket fitted provides fixed inclination of 30 degrees and is optimised for latitude 52 degrees north. For extremes of latitude an alternative bracket may be required.
PyrBkt This is a pole mount robust bracket pre-drilled for use with the Kipp and Zonen CMP3 and the SKS1110.
The mounting bracket positions the centre of the CMP3 approximately 155mm from the mounting pole. A stainless steel U bracket with securing nuts is included.

Common Specification

RF specification: EN300-220
RF power: 10mW
Environment specification  
  Compliant to EN300-220: -10 to +55°C
  Actual: -30 to +65°C
  Humidity: 100% non condensing
Environmental rating: IP40
Dimensions (footprint): 78 x 41mm
Battery endurance: up to 5 years (interval set to 5 minutes) (less for GL-70 and GS40 series)
Transmission interval range: 1 sec to 4 hours
Indicator (red LED): transmit active/on/off
Control switch (concealed): test mode / hibernate
Antenna socket: SMA

Transmitter Specification

Model(s) Sensors Range Resolution Accuracy
TMET 1 x u type thermistor input -50 to 150°C 0.05°C (-5 to +75°C)
0.1°C (-25 to +100°C)
0.2°C (-40 to +125°C)
±0.1°C (-5 to +75°C)
±0.2°C (-25 to +100°C)
±0.4°C (-40 to +125°C)
  1 x voltage input for use with external device e.g. solarimeter types Kipp and Zonen CMP3 or Skye SKS1110 0-50mV 0.025% 0.1%
  1 x serial input for connection to Vaisala WXT520 or WMT52 The TMET transmitter interfaces digitally with the Vaisala WXT520 to derive:
Windspeed: 0-60m/s
Wind direction: 0-360°
Barometric pressure: 600-110hPa
Air temperature: -52°C to 60°C
Relative Humidity: 0-100%rh


Frequency: Default is 434.225Mhz (other frequencies are available)
Tx output power: 10mW ERP
Useable Tx interval: typically 10 seconds to 15 minutes
Size: 120 x 120 x 55mm (excluding antenna)
Weight: 560g
Connection strip: Standard 5mm pitch rising cage connector (included)
Antenna “TMET”: Supplied compressed spring, L=70mm, modified SMA base
Gain: -3db
Antenna connector: SMA socket is mounted on the TMET
Fixing: 4 x 4mm dia holes (fixing screws are NOT provided)
Battery type: customised (7.2v) 2.3Ah Ni-mH with built in temperature sensor
Battery endurance: typically > 5 days if battery fully charged and with Vaisala connected
Charging time: Using MP12U: typically 8 hours from discharged
Using SPTMET typically from discharged 1 day of full sun.
Max lead length to any connected sensor is 10M.

Common to all transmitters
Gen II Quick Start Instructions

Specific to this family of transmitters
TMET Leaflet

User Instructions
TMET User Instructions