03-31-2019, 05:35 PM
Good afternoon, getting up there, our van said it was 80 in some spots, 86 in others. I have no confidence in the van's temperature monitor, they changed the software for it a few weeks ago, so we'll see when it starts getting really hot. Before, the hotter it was, the higher the error. At 40° it was close, at 110°, it would read 125.
Another story: Years ago, we made temperature probes using thermistors, just like the ones that most vehicles us to measure temperature. I needed fairly good accuracy so I had the vendor fax me the spec sheet. It showed 1.5% accuracy across a range. Great, so we ordered a bunch and programed the microprocessor to fit the temperature/resistance curve. It wasn't long before our customer started to complain about inaccurate readings. Some investigation showed that the decimal point on the fax sheet was a blip in the fax, and it really was only accurate to 15%, not acceptable.
We had to replace all the probes and processors to conform to the new thermistor curve. That was before you could get all the info you needed on the Internet.
Another story: Years ago, we made temperature probes using thermistors, just like the ones that most vehicles us to measure temperature. I needed fairly good accuracy so I had the vendor fax me the spec sheet. It showed 1.5% accuracy across a range. Great, so we ordered a bunch and programed the microprocessor to fit the temperature/resistance curve. It wasn't long before our customer started to complain about inaccurate readings. Some investigation showed that the decimal point on the fax sheet was a blip in the fax, and it really was only accurate to 15%, not acceptable.
We had to replace all the probes and processors to conform to the new thermistor curve. That was before you could get all the info you needed on the Internet.
Don (ezdays) Day
Board administrator and
founder of the CANYON STATE RAILROAD
Board administrator and
founder of the CANYON STATE RAILROAD