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Surface Layer Scintillometer SLS40-A (ES)

The Scintec SLS40-A (ES) Scintillometer measures turbulence, heat flux and momentum flux by purely optical means. In combination with other meteorological sensors the system can determine latent heat flux or evaporation.

The SLS40-A has both built-in automatic beam steering and vibration correction. It is designed for operation on towers or other platforms which are prone to vibration or longterm-drift. Vibration effects are compensated by using the signal of four instead of two optical detectors.

Each SLS Series Scintillometer consists of a laser transmitter pointing at a receiver. Temperature fluctuations in the air cause variations of the light intensity captured at the receiver. The scintillometer evaluates such variations to yield turbulence information.

The line averaging over the optical path results in spatially representative data and outstanding temporal resolution – a critical edge over data collected from conventional point sensors. The scintillometer provides high sensitivity and accuracy – without mechanical flow distortion or any moving part.

The proprietary displaced-beam technique of the SLS Series Scintillometers opens up access to mechanical turbulence quantities (momentum flux, kinetic-energy dissipation rate) without need to feed in any external wind data.

Features
built-in automatic beam steering
correction for transmitter vibrations
easy installation and operation
crosswind option available
high temporal resolution
beam-displacement calibration
spatially averaging technique
no flow distortion
window heating

Specifications
Data output (includes but is not limited to)
Description
Structure parameter of refractive index fluctuations (Cn2)
Inner scale of refractive index fluctuations (l0)
Structure parameter of temperature fluctuations (CT2)
Dissipation rate of turbulent kinetic energy
Sensible heat flux
Momentum flux
Obukhov length
Path-average wind speed perpendicular to he beam axis (with crosswind extension)
Mean, standard deviation, minimum and maximum of intensity
Correlation coefficient of intensity
Data quality code
General Specifications
Parameter
Specification
Optical wavelength
670 nm ± 10 nm
visible/red
Mean output power
140 µW
laser safety class 1
Beam divergence
3.5 x 3.5 mrad
Path length
50 - 250 m
others optional
Integration time
1 s to 60 min
Supply voltage and current
12 V, 15 W
for transmitter, receiver and SPU
Data output
Ethernet, RS-232
6 GB storage
Operating temperature
-20°C to +50°C (-5°F to +120°F)
Dimensions and weight: Transmitter
52 x 11 x 11 cm / 3.0 kg
Dimensions and weight: Receiver
62 x 12 x 12 cm / 4.1 kg
Dimensions and weight: SPU
33 x 23 x 18 cm / 8.0 kg
Accessories
Power Supply
for BLS450, BLS900 and SLS Series

For operation of BLS450, BLS900 and SLS Series systems with AC power.

Tripod standard, height 1.80 m

The tripod provides sturdy support for the Transmitter and Receiver of BLS and SLS Series.

Tripod high, height 3.00 m

The tripod provides sturdy support for the Transmitter and Receiver of BLS and SLS Series.

Mounting Screw for BLS/SLS

The Mounting Screw secures the Transmitter and Receiver of BLS and SLS Series to a stable platform

Direct Meteorological Data Input DMI-1
for BLS and SLS Series

The DMI-1 option consists of a temperature sensor, a barometric pressure sensor, a small tower and cables to connect the sensors to the SPU.

Direct Meteorological Data Input DMI-2
for SLS Series

The DMI-2 option consists of two temperature sensors, a barometric pressure sensor, a small tower and cables to connect the sensors to the SPU, the additional temperature sensor is to measure the temperature gradient.

Real-Time Heat Flux Extension
for SLS Series

The Real-Time Heat Flux Extension contains two temperature, pressure and a combined temperature and humidity sensors for an accurate calculation of CT2 and sensible heat flux for all - unstable and stable - conditions.

Real-Time Evapotranspiration Extension
for SLS Series

The Real-Time Evapotranspiration Extension contains net radiation, two soil heat flux, two temperature, pressure, precipitation, and a combined temperature and humidity sensors for determining the evapotranspiration in terms of latent heat through the so-called energy-balance method.

Real-Time Basic Extension
for BLS and SLS Series

The Real-Time Basic Extension contains temperature, humidity, and pressure sensors for calculation of structure parameter of temperature and in the case of the SLS series also the dissipation rate of turbulent kinetic energy.

Real-Time Upgrade Aspirated Radiation Shield
for BLS and SLS Series

This set of two Aspirated Radiation Shields can be used with the Real-Time Heat Flux and Evapotranspiration Extensions for higher accuracy in temperature measurements.

Real-Time Sensor Interface Software
for BLS and SLS Series

The Real-Time Sensor Interface Software allows data from sensors from Real-Time Extensions or other weather stations connected to the Signal Processing Unit to be integrated into the SRun software.

Crosswind Extension SLSCW-1
for SLS Series

The Crosswind Extension allows of the horizontal wind speed component perpendicular to the optical propagation path.

Weather Station Port Cable, 30 m
for BLS and SLS Series

This optional cable can be plugged into the Weather Station Port of the Signal Processing Unit, it can be used to have the BLS or SLS measurement data transmitted in real-time to your equipment.

Analog Raw Signal Output Cable, 3 m
for BLS and SLS Series

The analog out cable with open wires is optionally available to connect the Analog Out Port of the Signal Processing Unit to an external datalogger or other signal processing equipment.

Related Products
Surface Layer Scintillometer SLS20 (ES)

The Surface Layer Scintillometer for stable platforms or heavy tripods on solid ground.

Surface Layer Scintillometer SLS20-A (ES)

The Surface Layer Scintillometer with beam steering which permits operation when manual beam alignment is undesirable or difficult.

Surface Layer Scintillometer SLS40 (ES)

The Surface Layer Scintillometer for operation on towers or other platforms prone to vibration.