If you want to just get a quick check of temperature to make sure you are still on track, you can always insert a standard, glass, human temperature thermometer through one of the vent holes to get a temperature reading in about 3 minutes. The only problem I have found with these types of glass thermometers is that once they go up, they don't readily go back down without shaking them down. However, in my opinion, these glass thermometers are less likely than the inexpensive digital thermometers (designed for outdoor temp. measurements) to malfunction. I've observed one of my digital thermometers being dead-on accurate for weeks then without warning it went wacky and gave inaccurate readings (a few degrees high or low). I can always depend on my glass thermometers for a reality check before I panic and start adjusting the thermostat setting on the incubator.
