The Dial! I have had my best hatch after changing to a dial! All of my fertile eggs hatched. I am using a LG, still air, and hand turning. I did add a blanket of the entire unit with an air pocket at the top. I am getting ready for a hatch now and changed to digital this time. I am not sure I am liking it though. I get unlimited eggs for free from my neighbor so experimenting is not costly for me.
I've always been told that the dials are NOTORIOUS for being inaccurate because they are spring loaded. Supposedly the prong has a spring attached to it some kind of way, and through normal handling the spring inside gets stretched, therefore causing an inaccurate reading?
I have both in my incubator now. The glass one reads 99.5 all the time, but the dial is consistently 5 degrees off, and it usually reads lower than the glass one....
I have used glass, dial and digital. Personally the glass has always been more accurate. I calibrated my digitals and I can keep humidity ok because I know how off the humidity reads. I forked over good money for an instant read to check and the glass holds truer.
Chris, Why don't you try calibrating the dial thermometer? Here's the GQF instructions at the bottom of page 1. https://www.gqfmfg.com/pdf/3018 instructions.pdf
They say to try to set it up near the operating temp of 100 degrees. I suppose that comparing it with a known accurate thermometer in a glass of warm water would work well. I have also read that you can set them up using a glass of ice water and adjust it to read 32 degrees. Then see how they compare. Who's to say that the glass tube is properly positioned on its holder and hasn't shifted either up or down, skewing its reading?
I use both digital and glass thermometers. In particular I found that a basal thermometer (the kind used to track the ovulating cycles of women trying to become pregnant) is fairly accurate. The range something around 98 degrees F. to about 102 F. I think the scale for my basal thermometer is in tenths of a degree. So I figure smaller range, smaller scale, odds are it is more accurate than those inexpensive thermometers that come with most incubators. The one negative to a basal thermometer is that it must be shaken down repeatedly to be reset. However, that means it is useful for recording maximum temperature or temperature spikes in an incubator. I use one now just to validate a digital thermometer. I bought my basal thermometer for less than $10.00 at Walgreens in the baby making supply section.
I have tried almost ever thermometer out there. First it was accurite, then it was Flukers, and the ones that come with the incubator LOL dont work. They would work for a while then just, bam! I get all these wierd readings. The one I have had a long time is the Brinsea spot check and it has been right on. http://www.brinsea.com/products/thermo.html
I've been through numerous thermometer/hygrometer tools over the years. My favorite is the GQF dial, which I use for web bulb readings in my Sportsman. Second place goes to the Taylor digital and Accurite digitals, which I use in my Hovabators and my home made hatcher (refrigerator) unit.
I've tried the one that comes with most bators and they have always been significantly off (5 degrees or more). I didn't care for other mercury style cheapo models either..they work once and never again (seem to get stuck in position). ugh The Flukers was unimpressive for maintaining consistent temps/humidity readings as well. Just my observations.