Menu Close

MS-21 Pyrgeometer


Make:  Eko(Japan)      Model:  MS-21
✅ NEW thermal coupling design, outstanding low thermal resistance.
✅ WISG traceable calibration.
✅ 4.5µm – 42µm flat spectral response.
✅ Low temperature dependency, excellent stability.
✅ Designed & built for ultra-low window heating.
✅ 5-year warranty & EKO quality guarantee.

Designed to raise the bar, the MS-21 Pyrgeometer is research-grade, accurate, robust and delivers superior stability independent of the sensors’ operating temperature. Based on a new design concept and built for consistency, the MS-21 minimizes temperature differences and suppresses window heating errors.

Whatever the conditions, the MS-21 measures longwave downwelling radiation and longwave net radiation in a wide spectral band without needing a sun tracker with a shading device or shadow ring. It features a silicon meniscus dome with solar blind interference filter and hard carbon coating, a new thermal coupling design, onboard temperature compensating electronics, and a unique aluminum alloy sun shield.

With a 5-year Warranty, World Infrared Standard Group (WISG) traceable calibration, and PT-100/4W IEC60751 Class A Industrial platinum resistance thermometers and temperature sensors; the MS-21 achieves the highest standards for quality, accuracy, and reliability.




MS-21 Pyrgeometer

General Specification


Weight (Mass)



Voltage (mV)

Measuring Range

Net radiation measurement range : – 250 to 250 W/m²

Non Linearity

< 1 %

Temperature Response

< 1 % (-20° to +50°)

Field Of View


Operating Environment

-40° … +80°

Response Time

< 18 Sec (@95%)

Zero Offset B

< 1 W/m²


10 to 20uV/W/m²


100 to 200Ω