Product review (5 stars): Extech Humidity Meter
The Extech 445815 humidity meter works very well, right out of the box.  I have not calibrated the unit, but I only use the device to verify relative humidity for household comfort.  The unit reacts very quickly to humidity changes.  I take the unit outdoors to check its reading against the weather report and it usually is within 2-3 percent of the reported value.  It immediately returns to the previous indoor reading (45-48 percent) when it is brought inside.<a data-hook="product-link-linked" class="a-link-normal" href="/Extech-445815-Humidity-Meter-with-Alarm-and-Remote-Probe/dp/B000GFCN1I/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Extech 445815 Humidity Meter with Alarm and Remote Probe</a>