The purpose of this resource in Kala Patthar station is to acquire data on:

- wind speed

- wind direction

- global solar radiation (W/m2)

- UVA radiation (W/m2)

- wind speed (m/s)

- wind direction (degree)

- total precipitation (mm)

The DNA022 Lsi-Lastem combined wind speed-direction sensor is mounted on a 5m pole on Kala Patthar station in 2008.

The CombiSD sensor includes, in a single apparatus, the both transducers for measuring wind speed and wind direction. Its use simplifies the installation and the plant design in respect of the sensors with separate measurements plus giving some other advantages being smaller, lighter and cheaper. The CombiSD DNA022: sensor has a direct signal output. Frequency (Hz) for wind speed and resistance (Ohm) for wind direction. The CombiSD has low power consumption, it can be used in systems with small energy availability.

The technical characteristics are:

- Principle of operation: 3 cups and vane anemometer

- Speed sensor: Optoelectronic disk

- Direction sensor: 2000 Ohm wire potentiometer / Positioning Hall effect sensor

- Housing: Heavy gauge anodised aluminium

- Shaft carriers: Low-torque stainless steel bearings

- Protection (vertical position): IP65

- Mechanical mounting: On 48 50 mm diameter mast

- Electrical outlet terminators: IP65 watertight connector

- Weight (instrument with rotors): 950 gr.

The Physical and operational specification are:

- damage threshold > 75 m/s

- operating temperature: -30°+70°C

The speed measures are specified by:

- Measurement range: 0-60 m/s (using transfer function)

- Threshold: 0,21 m/s

- Response time (63% at 5 m/s): 0.8 s

- Distance constant (delay distance) at 5 m/s: 4 m

- Resolution (integration time=1s): 0.05 m/s

- Accuracy & Linearity: 0,1 m/s+1%VL (readout), if connected to LASTEM data loggers.

The direction measures are specified by:

- Measurement range: 0 ÷ 360

- Threshold: 0,15 m/s

- Response time (at 5 m/s): 0,26 s

- Delay distance (at 5 m/s): 1,32 m

- Damping coefficient (VDI3786): 0,21

- Transfer function: Dir(°)= 355 x R(Ohm)/2000

- Resolution: 0,1

- Accuracy: 1% FS (Full scale)

- Integral linearity: 0,5%