Weather stations
Scientific and educational studies
Pollution monitoring

Environmental monitoring
Vicarious Calibration

Irradiance based calibration of imaging sensors


High accuracy.

Highest grade filters are embedded into a solid cast aluminum housing which assures accurate, stable optical alignment. Low noise electronics and a 20 bit A/D converter allow high linearity, resolution and dynamic range.

Ease of use.

No computer knowledge is necessary to make measurements. Just aim the meter at the sun, align the image of the sun with the cross-hairs and push the button. In few seconds the measurement will be completed and the result stored in memory.


A small hand-held device is all you need to perform measurements. No additional computer is necessary.

Instantaneous results.

The Aerosol optical thickness calculation algorithms are programmed in the MICROTOPS II and the final results of all stored scans can be conveniently viewed on the LCD. The raw data is also stored to allow retrospective adjustments of algorithms.

Non-volatile memory.

The raw data collected by the MICROTOPS II, as well as calculated results are stored in non-volatile memory. Each data point is annotated with date, time, site coordinates, solar angle, altitude, pressure and temperature.

Low cost.

By implementing the latest technology, instrument cost has been brought well below that of comparable sunphotometers, without sacrificing accuracy or features.

Computer interface.

Connection to a PC through a USB interface enables transfer of collected data. MICROTOPS Organizer, a Windows-based software automates data retrieval and archiving.

Optical Channels:

340 ± 0.3 nm, 2 nm FWHM
380 ± 0.4 nm, 4 nm FWHM
440 ± 1.5 nm, 10 nm FWHM
500 ± 1.5 nm, 10 nm FWHM
675 ± 1.5 nm, 10 nm FWHM
870 ± 1.5 nm, 10 nm FWHM
936 ± 1.5 nm, 10 nm FWHM
1020 ± 1.5 nm, 10 nm FWHM

Stray light:

340nm: 1E-6 λ<650nm; 1E-5 λ<1.0μm
380nm: 1E-6 λ<650nm; 1E-5 λ<1.0μm
440nm: 1E-5 λ<1.0μm
500nm: 1E-6 λ<1.1μm; 1E-5 λ<1.2μm
675nm: 1E-6 λ<1.1μm; 1E-5 λ<1.2μm
870nm: 1E-6 λ<1.1μm; 1E-5 λ<1.2μm
936nm: 1E-6 λ<1.1μm; 1E-5 λ<1.2μm
1020nm: 1E-6 λ<1.1nm; 1E-5 λ<1.2μm



Dynamic range:


Viewing angle:




Non linearity:

max 0.002% FS

Operating environment:

0 to 50°C, no precipitation

Computer interface:


Power source:

4xAA Alkaline batteries


21 oz (600 grams)

Size: 4"W x 8"H x 1.7"D (10x20x4.3 cm)

Microtops® II calibrations are carried out using a Langley plot. NIST N/A. [Hold]


• Aerosol Microtops II sunphotometer observations over Ukraine, V. Bovchaliuk1∗ , A. Bovchaliuk1 , G. Milinevsky1 ,V. Danylevsky2 , M. Sosonkin3 , Ph. Goloub4, Advances in Astronomy and Space Physics, 3, 46-52 (2013): 046-052-BovchaliukV.pdf



Microtops II Sunphotometer Owners Manual (418K)
Maritime Aerosol Network (MAN)
A Comparison of the New Filter Ozonometer MICROTOPS II with Dobson and Brewer Spectrometers at Hohenpeissenberg (108K) U. Kohler - Reprint from Geophysical Research Letters
Atmosphere Poster (363K) Presented at Quadrennial Ozone Symposium Charlottesville, Virginia, USA June 4-13 1992 Daniel Berger, Marian Morys
Absolute Measurement and Modelization of 305.5 nm Direct Spectral Solar Radiation in Rosario, Argentina (43K) Work published in Spanish in "Avances en Energias Renovables y Medio Ambiente", Vol. 2, 11.53-11.56 (1998)
Ship-Based Sun Photometer Measurements Using Microtops Sun Photometers Porter et al, Journal of Atmospheric and Oceanographic Technology, Vol. 18, 765-774, 2001
Guide to RealTerm serial communications program for downloading Microtops Data NERC UK Guides
GPS Receiver with Data Cable
Tripod Adapter
A new carrying case for the MICROTOPS II® has just arrived.  It provides excellent protection and toting convenience, perfect if you’re traveling by car, ship, plane, or you’re in the field.  Check out some of the features below:
  • Well padded, durable constructioncase
  • Adjustable shoulder strap
  • Pouch for notepad, pencils, etc.
  • Velcro strap to attach fellow GPS carrying case
MICROTOPS II® is fully operable while inside case
Included Accessories
Required Accessories
Solar Light provides free telephone technical support for the life of our products.
We also provide a 1 year Standard Warranty on all of our products covering parts and labor.
Extended Warranty Plans are also available.