Home Products Alat Kualitas Udara Alat Ukur Cuaca Net Irradiance Meter LPNET07 (Delta OHM)
Net Irradiance Meter LPNET07 (Delta OHM)

LP NET 07 measures the net radiation across a surface, from near ultraviolet to far infrared. The Net radiation is defined as the difference between the radiation that reaches the upper surface and the irradiation on the lower surface of the net radiometer.

The surface of the upper receiver measures the direct solar radiation plus the diffuse one and the radiation at longer wavelengths emitted from the sky (clouds), while the lower receiving area measures the solar radiation reflected from the ground (albedo) and the radiation length wavelengths emitted from the earth. The instrument is designed and constructed to be used outdoors in any weather conditions.

Working Principle

The net radiometer LP NET 07 is based on a thermopile sensor whose warm joints are in thermal contact with the receiver while the upper cool joints are in thermal contact with the lower receiver. The temperature difference between the two receivers is proportional to the net irradiation. The temperature difference between hot and cold junction is converted into a voltage by Seebeck effect. The two receivers are made from a portion of spherical coated Teflon® . The particular form of the two receivers provides a response in accordance with the cosine. The Teflon® coating, as well as allowing outdoor installation for long periods without risk of damage, can have a constant spectral response from ultraviolet (200nm) up to far infrared (100 µm).

Installing and mounting the net radiometer for total irradiance measurements:

  • To allow cleaning the two receiving surfaces regularly, LP NET 07 should be mounted in easily reachable places. The surfaces can be washed with plain water or pure ETHIL alcohol.
  • Mount the instrument so that no shadow will be cast on it at any time of day and of the seasons, from obstructions such as buildings, trees, or any other obstacle.
  • In the NORTHERN hemisphere, the net radiometer is normally oriented towards SOUTH, while it should be oriented NORTHWARD, in the SOUTHERN hemisphere.
  • The instrument should be mounted at a height of at least 1.5 m above the ground. Please note that the flow on the lower receiver is representative of a circular area with a radius of 10 times the height.
  • When installing the net-radiometer avoid, wherever possible, to touch the surfaces of the receiving net-radiometer.
Technical specifications:
Typical sensitivity: 10 µV/(W/m2 )
Impedance: 2Ω ÷ 4 Ω
Measuring range: ±2000 W/m2
Spectral range: 0.2 µm ÷ 100 µm
Operating temperature: -40 °C ÷ 80 °C
Weight: 0.35 Kg
Response time (95%): <75 sec