BP moving from Hot to Cool side A LOT! What does this mean??

Quote:

---

Originally Posted by kitedemon

I have never really found a reasonably priced thermometer of any sort that was good, IR guns included, they are the same specs as the unit I posted. Most are +/-2ºF and some are worse. They are a useful tool as long as you keep the limitations in mind they do not really like shiny objects (smooth plastics for example) and do best pointed at something that reflects about as much light as a brown paper bag. They can give a good idea of gradients and spot temps but they cannot provide a precise measurement. They just do not work that way.

Sadly I calibrate instruments that require less than 0.5ºF in error and I have some very good thermometers and thermal couplers. The general thermometers used in the hobby are poor at best. This is why I suggest a number to be able to separate out the worst ones. I typically see a range of 2-3ºF from each other in a sampling group of 20 units the unit I linked earlier usually in 2ºF of correct (on the specs) the average is close to correct often being only 0.7ºF off.

---

Isn't there a quick test you can do at home to check the variance of your thermometers? Something to the extent of getting a bowl of ice and then filling it with water, waiting a few minutes then checking temps of the water? This is how the local food health department says to check thermometers for food storage, etc....

Quote:

---

Originally Posted by Zombie

This is how the local food health department says to check thermometers for food storage, etc....

---

All Health Department do;)

Quote:

---

Originally Posted by PitOnTheProwl

All Health Department do;)

---

Just wasn't sure cause Kite is in Canada :)

Yes you can and be fairly confident of being in a 3º range. That is the kicker, water freezes at 0ºC 32ºF Ice is at or below this temp. Water with ice is likely close to freezing but not exactly. Better would be to place water into the freezer and when a skin of ice forms stir it and likely it will be with in one degree. The other problem with printed resistant sensors is that the variation at freezing will it be the same at 80ºF ? Maybe and maybe not.

Getting to +/-4ºF is easy an cheap simple tests can easily manage. +/-2ºF is a bit harder but no great stretch (why many thermometers are spec'd to this point) +/- 1ºF is much more difficult and costly and breaking the sub 1º error is very costly that is why the better proportional T-Stats (herpstat ecozone, herpkeeper and helix) are all in the just under 1º area (0.7-0.9º +/- I believe) they manage this by not trying to probe the sensor to electronics the probe contains the electronics reducing the error incurred by having a wire. (I have not seen written specs on the VE series just word of mouth that it is under 1º hopefully someday they will get around to a complete manual) To break the 0.5 requires different methods usually thermal couplers or RTD systems often made of platinum. These have the highest accuracy and repeatability and the greatest cost. The three I use are worth more than 2500$ total. The cheap ones are often in the 350$+ range.