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Our Newsletter


Light Temperature Net Radiation Chlorophyll Concentration Oxygen
Atmospheric Pressure        



Apogee Instruments' quantum sensor measure photosyntheticall active radiation, PAR

Photosynthetically Active Radiation (PAR)

Radiation that drives photosynthesis, PAR, is typically defined as total radiation across the 400 to 700 nm range. PAR is often expressed as photosynthetic photon flux density (PPFD) in units of µmol m-2 s-1. Sensors that measure PPFD are often called quantum sensors due to the quantitzed nature of radiation.

Apogee Instruments' pyranometers provide accurate and stable global shortwave radiation measurement

Shortwave Radiation

Solar radiation at Earth's surface is typically defined as total radiation across a wavelength range of 280 to 4000 nm (shortwave radiation), and is expressed in W m-2. Pyranometers are sensors that measure global shortwave radiation.

Apogee Instruments' UV sensors measure UV radiation from 250 to 400 nm

Ultraviolet Radiation

UV Radiation from sunlight is subdivided into three wavelength ranges: UV-A (320 to 400 nm), UV-B (280 to 320 nm), and UV-C (100 to 280 nm). Apogee UV sensors detect UV radiation from 250 to 400 nm and are calibrated in photon flux units of µmol m-2 s-1.

Apgoeee Instruments' spectroradiometers provide absolute spectral measurement across a wide wavelength range

Spectral Radiation

Spectral radiation is intensity of output from a radiation source as a function of wavelength. Radiation spectra vary for different radiation sources and vary with conditions. Radiation spectra can be used to characterize radiation sources. Spectrometers measure relative spectral radiation over a specified wavelength range. Spectroradiometers are spectrometers calibrated to output spectral measurements in absolute units.



Apogee Instruments' temperature sensors have a wide measurement range, -50 to 70 C

Thermistors and PRT's

Thermistors and platinum resistance thermometers (PRTs) are widely utilized in applications measuring temperature. Fan-aspirated Radiation Shields can be used to get more accurate temperature measurements.

Infrared radiometers measure temperature

Infrared Radiometers

Infrared radiometers are sensors that measure infrared radiation, which is used to determine surface temperature without touching the surface. Infrared radiometers are often called infrared thermometers because temperature is the desired quantity, even though the sensors detect radiation.

Apogee Instruments' radiation frost detectors provide on-site, real-time warning of radiation forst events

Radiation Frost Detection

On clear, calm nights, plant leaf and flower bud temperatures can drop below freezing even if air temperature remains above 0 C. This is called a radiation frost and is due to the lack of air mixing near the surface, and a negative net longwave radiation balance at the surface. Apogee radiation frost detectors are designed to approximate plant leaf and flower bud temperatures for prediction of frost events.


Net Radiation

Apogee Instruments' net radiometre provides four-component measurement of net radiation with black-body pyranometers and pyrgeometers

Net Radiometer

Net radiation is the sum of net shortwave radiation, difference between incoming shortwave (from the sun) and outgoing shortwave (reflected by surface), and net longwave radiation, difference between incoming longwave (emitted by molecules in atmosphere) and outgoing longwave (emitted by elements at surface). Net radiometers are instruments designed to measure net radiation.


Chlorophyll Concentration

Chlorophyll meter measures chlorophyll concentration in absolute units

Chlorophyll Concentration Meter

Chlorophyll concentration in plant leaves is typically expressed in units of quantity per area of leaf surface [µmol m-2]. The patent pending MC-100 Chlorophyll Content Meter measures relative chlorophyll content and outputs an estimate of actual chlorophyll concentration, providing an alternative to destructive sampling techniques for determining chlorophyll concentration.



Oxygen sensor measures 0 to 100 % gaseous oxygen

Oxygen Sensor

Oxygen (O2) is the second most abundant gas in the atmosphere and is essential to life on Earth. While the absolute oxygen concentration O2 determines the rate of most biological and chemical processes, the relative O2 concentration is typically reported, and expressed in terms of a percentage of O2 relative to the other gases in the mixture. Apogee offers Oxygen sensors to measure 0 to 100 % gaseous O2.


Atmospheric Pressure

Apogee Instruments' barometric pressure sensors are accurate, stable, and durable, at an affordable cost

Barometric Pressure Sensor

Atmospheric or barometric pressure is the force per unit area exerted on Earth's surface by the mass of air overlying the surface and is typically expressed in the unit killopascals [kPA]. A barometric pressure sensor is used to determine atmoshpheric pressure.