Kestrel 3500DT Pocket Wind Meter

The Kestrel 3500 DT was designed specifically to meet the needs of agricultural professionals who require accurate, fast Delta T readings.  While the Kestrel 3500 DT has many features, it is the only meter to provide the Delta T measurement, and it was designed specifically with farmers in mind.

To ensure safety and effectiveness when spraying, it is critical to measure relative humidity, wind speed and wind direction. Many locales regulate the maximum permitted wind speed during spraying to minimise spray drift. In hot, dry conditions, expensive chemicals may evaporate into the air rather than onto your crops. However, you can minimise costly evaporation by selecting an appropriate nozzle and increasing the spray droplet size.

The Kestrel 3500 DT incorporates a Delta T calculation, the spread between the wet-bulb temperature and the dry bulb temperature (in degrees C or F). Delta T offers a quick guide to determining acceptable spraying conditions. For example, it is not recommended to apply pesticides when Delta T is above 10 — a range of 2 to 8 is ideal. With the Kestrel 3500 Delta T, the calculation is done for you accurately and simply.

The Kestrel 3500 Delta T incorporates barometric pressure correction in its wet-bulb temperature calculation, ensuring accuracy even on low-pressure days, at high altitudes, and in very dry weather when Delta T monitoring is important. No other pocket weather meter offers this feature with this level of accuracy.

A new model with LINK Bluetooth, stores data for export, works with Android and iPhone while measuring Delta T is the new Kestrel 5200.

In addition to offering highly accurate readings designed with the needs farmers and other agricultural professionals in mind, the Kestrel 3500 Delta DT is a reliable piece of equipment that can save you thousands of dollars in waste each year.  When you access to the reliable readings that you need the most in your line of work, you can start to streamline your efforts and maximize your spraying budget.   It’s the ideal blend of simplicity and technology that makes the Kestrel 3500 Delta T the number one choice for agricultural professionals.

Every Kestrel is individually calibrated to NIST-traceable standards and comes with a free Certificate of Conformity (Individual NIST certificates and recalibration are also available.) If your application demands regular calibration, simply pop in a new impeller and the Kestrel air velocity meter is restored to like-new factory calibration standards.

What is Delta T?

The Kestrel 3500 Delta T Meter is one of our most popular sellers due to its crucial utility in farming applications.  However, some don’t fully understand what it is and why it’s so important to take Delta T measurements before crop spraying.

Specifically, Delta T is the difference between the Dry-bulb and the Wet-bulb temperature.  This measurement is crucial because the Delta T plays a major role in thermal drift, which is a result of unstable meteorological conditions. If not properly considered, chemical droplets can be carried on thermal eddies and deposited some distance away from the target site.

The Kestrel 3500 Delta T incorporates barometric pressure correction in its wet-bulb temperature calculation, ensuring accuracy even on low-pressure days, at high altitudes, and in very dry weather when Delta T monitoring is important. No other pocket weather meter offers this feature with this level of accuracy.

Delta T has become one of the standard indicators for acceptable spray conditions. It is indicative of evaporation rate and droplet lifetime.  The diagram below relates air temperature and relative humidity to values of Delta T: