Hand-held meteorological measuring instruments from the American company Kestrel. For measuring and storing wind speed, temperature and other meteorological data.
Reliable and accurate data in the size and price of a mobile phone.

What makes Kestrel Instruments so special?

Nielsen-Kellerman has been researching, designing, manufacturing and marketing Kestrel Weather and Environmental Meters for over 20 years. The NK team consists of experts and engineers who are dedicated to creating the most accurate and reliable portable weather instruments. They are constantly committed to improving the Kestrel range and creating new products to meet customer needs.

Certified and guaranteed accuracy

Each Kestrel Weather and Environmental Meter manufactured by NK is calibrated for each reading either directly against NIST traceable standards or against an intermediate standard that is calibrated daily. (The National Institute of Standards and Technology is the federal technology agency that works with industry to develop and implement technology, measurements, and standards.) Each unit ships with a free Certificate of Conformity that lists what calibrations have been performed and certified performance specifications. What does this mean for the customer? They can be completely confident that their weather readings meet the required specifications. Some competing weather instruments claim the same specifications as the Kestrel, but only the Kestrel certifies its accuracy. For an additional fee, NK can even provide a NIST-traceable Certificate of Calibration that specifies exactly which values ​​were measured during each multi-point calibration and details the calibrated standard used for testing. A 30-day satisfaction guarantee even covers accuracy concerns. If a customer questions the accuracy of their unit after purchase, they can contact us and we will recheck all calibrations to ensure the unit meets specifications.

American made

The entire Kestrel line is designed and built in the USA - no other portable weather instrument is. Some electronic components these days have to come from overseas, but we buy American made wherever possible. We believe that American manufacturing is the only way to ensure that every Kestrel does its job well, and we also believe it is important to be involved in keeping American manufacturing alive and growing.

Patented removable impeller

The Kestrel's impeller is 1 inch and mounted on a nylon bearing. Its large size ensures accurate readings even when viewed from an angle other than the wind, and its very low starting speed enables the measurement of even the lightest of gusts. Units with smaller impellers simply cannot compete with the Kestrel's performance at low wind speeds. If it's damaged, you can buy a new calibrated impeller and snap it in without tools, restoring brand new performance. We designed and patented this detachable impeller technology and it ensures that Kestrel Meters measure wind speed accurately for years to come.

Patented RH measurement with two temperature sensors

Measuring relative humidity is tricky - especially in a sealed product. But as some of our leading customers in wildland fires, we know it's imperative that we get it right. Firefighters usually work in extreme conditions with very low humidity and their lives literally depend on accurate readings. Accurate temperature measurement is critical to calculating relative humidity. Therefore, NK developed the patented Kestrel dual temperature sensor configuration. There is no need to wait the 20-40 minutes that would normally be required for the unit temperature to equilibrate with the air temperature after the temperature change. If the air flow is maintained on the temperature-sensitive sensor, either by keeping it in the ventilation or swinging it in the air, the outdoor temperature sensor immediately and accurately gives a reading of the outdoor air temperature, while the second sensor in the humidity chamber provides the critical information about the temperature of the indoor unit (even even if it differs). Kestrel then performs the calculations necessary to achieve the claimed accuracy (which is usually only found in the several hundred dollar units). The Kestrel relative humidity sensor has been selected for long-term stability and reliable performance, even in very low and very high humidity conditions. All Kestrels are calibrated to NIST-traceable standards and can be recalibrated in the field with the Kestrel RH kit.

Patented temperature measurement

Unlike most watches and other products, the Kestrel's sensor is located outside the case to ensure it measures the air, not your hand or pocket. The "bugs" serve as additional insulation from the effects of the case's temperature. Again, simply shake the Kestrel a few times and you'll get accurate air temperature readings in seconds. And because the Kestrel is completely waterproof, you can actually take water temperature and snow temperature readings - simply submerge the sensor in water or snow. Just ask the US Biathlon team - at the 2006 Winter Olympics they used Kestrel 4000s to measure air and snow temperatures to determine which wax was optimal for their skis.