Kestrel RH Calibration Kit for Kestrel 3000 3500 4000 Series Black 0. This manual explains the steps for calibrating the humidity measurement for the Kestrel. The large container is used to create a stable environment. The small containers are used to hold the saturated salt solution. The saturated salt solutions generate well-defined humidity when they are confined to a contained environment. Specifications for Kestrel Rh Calibration Kit: Manufacturer: Kestrel Color: Black Additional Features: For Kestrel 3000 3500 4000 Series Weight: 1 lb Water Resistance Level: Waterproof Package Contents: Kestrel Rh Calibration Kit Kestrel Rh Calibration Kit The Kestrel Rh Calibration Kit is a quality addition to the Kestrel lineup. For more great deals on Weather Instruments by Kestrel please browse our Kestrel Camp & Hike page. Kestrel Rh Calibration Kit