Search metadata

At the AWS Pheriche station the CombiSD DNA022 Lsi-Lastem combined wind speed-direction sensor is mounted on a 5m pole. 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%

At the AWS Askole station the DQA035 Lsi-Lastem rain gauge is mounted on a 1,5 m mast. This model of Rain gauge has a 1.000 cmq collector area. The measurement device is composed of a collector cone and a double chamber bascule connected to a magnete that operates one (optional two) reed switch, which generates impulses that can be counted by external meters: each impulse is equal to 0.2 mm of rain (optional from 0.1 to 0.5 mm). The mechanical and electrical specifications are: - Collector surface area: 1000 cmq - Collector area diameter: 420 mm - Measurements range: 180 mm/hr - Resolution: o,2 mm/imp. (opt. 0,1; 0,3; 0,4; 0,5; mm/imp.) - Accuracy: 0-1 mm/min: 1% 1-3 mm/min: 2% 3-5 mm/min: 4% 5-10 mm/min: 8% - Contact: 1 reed (opt. N.2 reed) 0,5 A/24V non inductive - Pulse duration: 100 msec.± 5 - Collector cone material: Brass - External housing material: Inox AISI30 - Tipping bucket material: Alluminium - Cable: 10 m - Weight: 6,3 kg - Power supply: /thermocover 100 W, 24 Vca/Va

Since 2014, the Digital Barometer PTB330, by VAISALA, is installed. Vaisala BAROCAP® Digital Barometer PTB330 is a new generation barometer, designed for a wide range of high-end atmospheric pressure measurement. -Vaisala BAROCAP® sensor -Accurate measurement -Excellent long-term stability -Added reliability through redundancy -Graphical trend display with 1-year history data -Altitude corrected pressure (QFE, QNH) -For professional use in meteorology, aviation, laboratories, and demanding industrial applications

The Multi Angle Absorption Photometer (MAAP (MAAP 5012, Thermo Electron Corporation) is installed at the Nepal Climate Observatory - Pyramid for the measurement of the Black Carbon concentration unit [ng/m3].

This instrument uses a tipping-bucket mechanism to produce a contact closure every time it receives a predetermined small quantity of rainfall (0.2 mm). The body and funnel of the gauge are of aluminium alloy. An accurately machined septum-ring at the top gives an aperture of exactly 400 cm 2 . The tipping-bucket mechanism is mounted inside the body on a cast aluminium-alloy base equipped with fixing slots, three levelling screws and a spirit level. The mechanism consists of a divided bucket pivoted at its centre. Rain collects in the upper half. When this is full, the mechanism tilts and discharges the collected water, allowing the other half of the bucket to begin filling. A siphon device is fitted to the base of the funnel to control the rate of flow into the buckets. By ensuring a constant flow rate into the tipping bucket, calibration is made easier and accuracy improved. The alternate filling and discharging continue as long as rain is falling, and at each tilt, magnet momentarily closes the contacts of a reed switch. In the rain gauge of type RG13H, a heater element is provided inside the body in order to melt snow. The heater switches on at temperatures below +4 °C. Technical Specifications Diameter of aperture: 225 mm Area of aperture: 400 cm2 Rainfall capacity unlimited Sensitivity (rainfall per pulse) : 0.2 mm Dimensions (height diameter): 390 300 mm Weight: 2.5 kg Heater (in RG13H) : 38 W/40 VAC Thermostat operation: Open at +11 ºC (±3 ºC) Close at +4 ºC (±3 ºC)

The Vaisala WXT520 multi-parameter weather transmitter installed at Nepal Climate Observatory -Pyramid is a compact and lightweight multi-sensor instrument that measures the most essential weather parameters. The meteorological parameters measured are air temperature, atmospheric pressure, relative humidity, wind speed and direction, precipitation.

At the AWS Pheriche station the CX115P Lsi-Lastem barometer iis connected with measurement system (recorder, data logger) that accepts analog signals. The barometer functions according to the piezometric principle: a resistive film is deposited on a slice of silica with a bridge form; as the pressure changes, the slice will deform and consequently changes the system's resistance. The CX115P model mounts a special thermal compensation system that significantly reduces drift. General characteristics: Range: 800 ž 1100 hPa (1 hPa=1 mBar) Sea level correction range: -300...+2000 mt. Thermal drift: 0,01 hPa/°C (-10..+60°C) Linearity&Hysteresis: < 0,3% of the range Overload: max. 2 Pa Load resi stance: Current output types: <500W. Power consumption: 3 W Response time (T90): 1 ms Environmental limits: -25 .. +60°C Output connections: terminals Weight: 650 gr. Housing case material: Plastic Protection: IP40 Downward cable outlet

At the Askole AWS the DMA572 Lsi-Lastem Thermohygrometer is mounted on a 2 m pole. It is a probe for measuring air temperature and air relative humidity with replaceable sensitive element for simplify calibration and maintenance. LSI-Lastem supplies a precise and reliable set of probes, suitable for a continuous measurement in severe environments, in presence of deep thermal and hygrometric ranges with high sun radiant heat. An important feature of this set of sensor is that the thermohygrometric sensitive element is easily replaceable, in order to have a simple and rapid ordinary maintenance and avoiding calibration. The Thermohygrometer has supported a considerable improvement, owing to a deep technical and styling development process: a fan ensures a continuos air change around the sensor in order to eliminate temperature fault caused by radiant heat. For temperature: Range -30.+70°C Sensitive element Pt100 1/3 DIN-B Accuracy ± 0,1°C (0°C) Hysteresis&Repeatability na Resolution 0,025°C Long term stability -0.04% (after 5 years at 200°C) Calibration uncertainty 0,1°C Response time (T63) Wind speed 0,3-0,5 m/s: 80sec Radiation shield efficiency with respect to forced ventilation sensor (wind 0,5m/s, rad.800 W/m2): +0,6°C For relative humidity: Range: Nom.0..100%, Eff.10..98% Sensitive element Capacitive Accuracy 2,5% (11-90%) 0,6°C (20°C, 50%RH) Hysteresis&Repeatability 0,5% Resolution 0,2% Long term stability -2%/year (at 75%RH) n.a. Calibration uncertainty 0,1°C 1,5% na Response time (T63) Wind speed 0,3-0,5 m/s: 80sec Radiation shield efficiency with respect to forced ventilation sensor (wind 0,5m/s, rad.800 W/m2): n.a. General characteristic: Ventilation: Natural Electric output Jumper locally selectable 2 x 0-20 mA, 4-20 mA, 0-5 V, 1-5 V. 60-300 mV Output signals Output n.1: temperature. Output n.2: RH% or dew point (default RH%) Operating temperature -30°+70°C Sampling rate 1 sec. (default) PC programmable 1..300 sec. N°acquisitions for mobile average calculation: N°1 (default), PC programmable 1..20 acquisitions Load resistance (mA output): DMA570 300 Ohm