SERIES HD 2021T
HD2021T*.** Transmitter for measuring the ILLUMINANCE, adjustable full scale *,
power supply 16…40Vac/dc. Output 0…10Vdc or 4…20mA **.
HD2021T1*.** Transmitter for measuring the IRRADIANCE, in the wavelength VIS-NIS, adjustable full scale, power supply 16…40Vac/dc. Output 0…10Vdc or 4…20mA **.
HD2021T2*.** Transmitter for measuring the IRRADIANCE in the wavelength UVA, adjustable full scale *, power supply 16…40Vac/dc. Output 0…10Vdc or 4…20mA.**
HD2021T3*.** Transmitter for measuring the IRRADIANCE in the wavelength UVB, adjustable full scale *, power supply 16…40Vac/dc. Output 0…10Vdc or 4…20mA.**
HD2021T4*.** Transmitter for measuring the IRRADIANCE in the wavelength UVC, adjustable full scale *, power supply 16…40Vac/dc. Output 0…10Vdc or 4…20mA.**
HD2021T6*.** Transmitter for measuring the LUMINANCE adjustable full scale *,
power supply 16…40Vac/dc. Output 0…10Vdc or 4…20mA.**

Measurement of solar irradiance, within 400nm ÷ 950nm spectral band (HD 2021T.1)
Monitoring tanning lamps irradiance within UVA (HD 2021T.2) and UV (HD2021T.5) spectral regions, as well as efficiency control in filters for high pressure UV lamps.

Efficiency control in UV lamps used in water purification plants, where UVC (HD2021T.4) band irradiance needs to be constantly monitored.

The HD2021T Transmitter for illuminance, luminance and irradiance series allows conversion of photometric and radiometric quantities as illuminance (Lux), luminance (cd/m2) and irradiance
(W/m2) - across UV, UVA, UVB, UVC spectral regions and 400-950nm band - into a 0 ÷10 voltage signal. The voltage output 0 ÷ 10 V ( 0 ÷ 1 V, 0 ÷ 5V, 4 ÷ 20mA upon request) comes factory set calibrated to the full scale range specified at the time of order. 
HD 2012T transmitters wide range of applications include:
Measurement of illuminance (HD 2021T ) and luminance (HD 2021T.6) in offices and laboratories, manufacturing plants and production areas, commercial sites, theatres, museums, sports lighting, roadway lighting, tunnels and nursery-gardening systems.

INSTALLATION OF TRANSMITTERS

After choosing the right position where to install HD2021T, we need to provide the electric connections inside the transmitter. Loosen the four screws on the lid in order to lift it; the inside of the transmitter will look as in figure n.1. On the terminal board we will locate three
terminals with the following tags: GND meaning the ground referred to power supply and output signal +Vcc where the positive pole of the power supply has to be connected (in case of continuous power being employed) Vlux (output) system output to be connected to the positive pole of a Multimeter or Data Logger.
The sample below shows the installation of HD2021T illuminance transmitter monitoring lamps intensity. For this kind of application, HD2021T transmitters are generally installed on ceilings, close to the area where illuminance needs to be monitored (figure 2). 
Through a reference Luxmeter (ex. DO9721 with probe LP9021 PHOT) previously placed in the operating area, we work on HD2021T potentiometer until we get to the desired reference value.
HD2021T output is able to control several adjustable feeders at the same time.