A novel instrumentation for the detection of AOD composed of components and resistant materials perfectly combined with an intuitive and easy to use software.

The ZEN system is a new radiometer (ZEN-R52) that uses an innovative methodology for the detection of AOD (ZEN-LUT). The ZEN-LUT method is based on the comparison of zenith sky radiation (ZSR) measured with a look-up table (LUT) of Sky Radiation Calculations (ZSR).

The first version was jointly developed by Sieltec Canarias and IARC (Spain) aiming at obtaining AOD data from the radiation of the zenith of the sky at different wavelengths. It incorporates collimation lenses and internal deflectors to achieve a field of vision of -2º.

The measurements, made simultaneously in all its channels, are amplified and then processed. Inside the device there are internal sensors for humidity and temperature control.

The new methodology and obtained results have been published in Atmospheric Measurement Techniques (20 February 2017):


A new zenith-looking narrow-band radiometer-based system (ZEN) for dust aerosol optical depth monitoring

  1. Fernando Almansa1,2,4, Emilio Cuevas1, Benjamín Torres3, África Barreto1,2, Rosa D. García1,5, Victoria E. Cachorro4, Ángel M. de Frutos4, César López6, and Ramón Ramos1

1Izaña Atmospheric Research Center (IARC), Meteorological State Agency of Spain (AEMET), Santa Cruz de Tenerife, 38001, Spain. 2Cimel Electronique, Paris, 75011, France. 3Laboratoire d’Optique Amosphérique, UMR8518, Université des Sciences et Technologies de Lille, Villeneuve d’Ascq, France. 4Group of Atmospheric Optics, University of Valladolid, Valladolid, 47011, Spain. 5Air Liquide España, Delegación Canarias, Candelaria, 38509, Spain. 6Sieltec Canarias S.L., La Laguna, 38230, Spain
Published: 20 Feb 2017. https://www.atmos-meas-tech.net/10/565/2017/




i-ZEN R-52

Sensor Silicon diode
Number of channels Up to 5
Wave lengths (*) 440, 500, 675, 870 and 940 nm
Field of view
Measurement rate 1 minute
Resolution 16 bit
Stray light Better than 10-5 (**)
Dark noise <5 raw counts
Thermal noise (-20° to 50°) <5 raw counts (VIS) or <50 raw counts (NIR)
Data output Raw counts on each channel

Standard deviation on each channel

Watt/m2 on each channel

AOD on each wave length

PWV (4Q 2018)

Internal temperature

Internal humidity

Sun position data

Software Capture


Data graphs


Export data

FTP backup

VPN access


Gigabit PoE LAN

Power supply Input: 90 – 240V (***)

Output: 15V, 25W PoE passive


Protection level >IP67
Window 75mm diameter borosilicate window, 6.5mm thickness
Case Top: anodized aluminium

Body: power coated aluminium

Internal extra heater 10W
Operating temperature -40° to 55° (with internal extra heating)
Blower Optional
Dimensions 170 mm height , 180 mm diameter
Weight 6 kgs (ZEN), 11.5kgs (total system packed)

(*) Other on demand

(**) with the use of the Sun blocking add-on

(***) Can be powered with solar panel