E1 Flashing on Kestrel Meter
If the unit is flashing E1:
The humidity on the meter needs to be re-calibrated.
If its absolutely brand new and you bought it from us, we'll take it back and send you a new one... (or let the company know who you bought it from). This shouldn't happen.
If its less than 12 months old... then NK, the manufacturer, will do it for you for free. Otherwise if its older, you can to pay to get it done through us ($65) or purchase a calibration kit (http://kestrelmeters.com/products/kestrel-meter-calibration-kit)