Ballistics weather meter KESTREL 3500NV 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.

Environmental measurements:

• Altitude (Barometric);
• Barometric Pressure;
• Dew Point temperature;
• Heat Stress index;
• Relative Humidity;
• Temperature;
• Wet Bulb temperature (psychrometric);
• Wind Chill;
• Wind Speed/Air Speed.

Features:

• 3-Button Control;
• Backlight - Night Vision Preserving Light Red;
• Data Hold Function;
• Date & Time;
• Drop-Tested to MIL-STD-810G;
• Field Humidity Calibration/Correction Routine;
• High Contrast, Sunlight Readable Monochrome LCD Display;
• Minimum/Maximum/Average Reading;
• Waterproof to IP67 (3'/1M for 30 minutes).

Includes:

• Battery - 1 x CR2032;
• Certificate Of Conformity (Spec Sheet);
• Instructions;
• Lanyard;
• Protective Cover - Hard Slip-on.