This unit has a night-vision preserving backlight which helps users to sustain natural night vision. The NV's backlight incorporates an optical filter to reduce overall brightness and minimize blue and green spectrum light to preserve night vision. Additionally, NV backlights are also much dimmer than a standard backlight, making it more difficult to detect with the naked eye in night operations. This backlight appears soft greyish pink, not red, and is still in the visible spectrum, so is not compatible with night-vision equipment.

It takes 30 to 45 minutes for the average eye to adapt to darkness and maximize night vision. Even a short burst of white, yellow, green or blue light “bleaches out” the rod cell photoreceptors in the eye and causes night blindness until the entire adaptation process can take place again. Light in the red spectrum does not cause this “bleaching out”, preventing night blindness and night vision fatigue.

Kestrel 3500 Measures

• Barometric pressure
• Pressure trend
• Altitude
• Relative humidity
• Heat stress index
• Dewpoint
• Wet bulb temperature
• Wind chill
• Air, water, and snow temperature
• Current wind speed
• Average wind speed
• Maximum wind gust

• Real-time clock
• Waterproof and floats
• Large easy-to-read display with backlight
• Data hold function
• High precision pressure sensor
• Quick response, external thermistor
• Forecast weather with pressure trend indicator
• Humidity sensor can be recalibrated in the field with our Relative Humidity Calibration Kit.
• Innovative, thermally adjusted humidity sensor designed for stability and accuracy in abrupt condition changes
• Patented user-replaceable impeller
• Reliable, portable and easy to use
• Protective cover with sure-grip overmolding
• All instruments and accessories are completely assembled in the USA
• 5-year warranty

• A slip-on protective cover
• Neck lanyard
• CR2032 coin cell battery (Average life 300 hours)
• Kestrel Certificate of Conformity

This is a special order item and is not normally stocked. Please allow 2-3 weeks for delivery.

Kestrel