These sensors, traditionally used in plant growth studies, count the number of quanta falling between 400 and 700 nm.
The PAR Quantum is the sensor with the ideal 100% quantum efficiency curve and is traditionally used in plant growth studies. The spectral response has been well researched and documented and is widely accepted as 'the standard'.
For measurement of total sunlight and for use in outdoor locations we offer the silicon cell Pyranometer, A very popular and cost effective sensor, which is calibrated against a WMO Class 1 Thermopile. Output is proportional to total solar energy in watts/m2
This sensor measures energy (rather than quanta) in watts/m2 within the 400-700nm waveband. This sensor is useful if studies involve the use of other instruments, such as Pyranometers, which also measure in watts/m2.
Lux or Photopic Sensor
The response curve of this sensor matches the CIE Photopic curve (a standard for human eye response to light) and measures in Lux units. This is the preferred sensor for human and animal studies.
Two sensors designed to measure the UVA (315-380nm) and UVB (280-315nm) parts of sunlight.
Components used have been selected for their stability in a UV environment. The bandwidth characteristics are tailored to DIN standards.
Red/Far Red Sensor
The Red / Far-Red (RFR) sensor is one of a range of Skye's light sensors for plant growth and research. It is second in popularity only to the PAR Quantum sensor in this field.
The sensor is a 2 channel radiometer, essentially two sensors in one. The specially designed light collecting head (fully Cosine Corrected) randomly splits light between two separately filtered photodiodes, giving a light intensity output for each of the red and far-red channels, ideal for measuring the RFR Ratio.
Specialised sensors for those who need to measure reflected as well as incident light at two or four different wavelengths. These units can be used either with or without the cosine collecting adapter in place on top of the sensor. Clearly with the adapter in place the light measured by the two or four channels of the sensor is from a cosine (hemispherical) distribution. If the adapter is removed, then the two or four channel narrow acceptance angle channels are exposed for use with light reflected from the surface to be studied. Wavelengths and bandwidths can be ordered between 400 and 1050nm.
Sensors for the Hansatech Leaf Chamber
A sensor designed especially for use with the leaf chamber produced by Hansatech Ltd. There is a choice of two spectral responses - the standard Quantum response (SKP 216Q) and a 550-750nm response (SKP 216ER) to match the LEDs used for leaf illumination
Fibre Optic Probe
A one or two channel radiometer with a long fibre optic probe extension. The light is collected from the tip of the probe at right angles to its long axis. Thus the probe can be inserted in short grass sward and collect down-welling light. The filters and diodes are housed in a small ABS box, which is neatly mounted with the measuring unit to make a compact hand-held system. The response of this probe can be can be chosen from the standard range of sensors, eg. PAR Quantum response
Fibre Optic Probe
NDVI is defined as the Normalised Difference Vegetation Index. NDVI is calculated from observations made by earth orbiting meteorological satellites such as LANDSAT, SPOT, NOAA AVHRR, MODIS etc.
The satellites record spectral reflectivity of solar radiation at specific wavelengths, allowing the monitoring of the density and vigour of green vegetation growth.
Errors in the satellite readings are caused by several atmospheric conditions such as small area clouds, scattering by dust and aerosols, large solar zenith angles etc. Skye sensors are used to make 'ground truth' observations to make corrections to the satellite recorded data.