A man with 2 clocks never knows what time it is

Discussion in 'Off Topic [BG]' started by hbarcat, Oct 4, 2022.

  1. hbarcat

    hbarcat Supporting Member

    Aug 24, 2006
    Rochelle, Illinois
    I have 2 temperature/humidity guages in my workshop but they never agree with each other.

    Obviously at least one of them is grossly inaccurate. Maybe both of them are.

    What I've been doing is just going with a value that's between the 2 numbers and calling it good enough.

    Maybe I should splurge on an expensive instrument that's more acurate and properly calibrated.

    This picture is typical of how they read. Often, they're off by even more than this.


    20221004_105923.jpg

    The difference in temperature is 2.2 F
    The difference in humidity is 5 percentage points.
     
    Last edited: Oct 4, 2022
  2. turf3

    turf3

    Sep 26, 2011
    It's easy enough to calibrate temp. Humidity's a bit more difficult. I guess I'd suspend the meter over a water bath in a closed container and ensure it reads 100% and then put it in a closed container with a bunch of fresh silica gel and ensure it reaches something like 5%.

    Since it's probable neither of these is actually adjustable for zero or span, you would want to make up a chart.
     
  3. I think you're on the right track with averaging. Buy another one and you have three clocks. Unless temp. and humidity need to be very tightly controlled spend the money on something fun.

    I used things like this to track temp. and humidity at my transmitter sites. Accuracy was less important than tracking trends over time. It was all relative, especially the humidity.
     
    hbarcat likes this.
  4. hbarcat

    hbarcat Supporting Member

    Aug 24, 2006
    Rochelle, Illinois
    I also have 2 clocks in my workshop. One of them is faster than the other and they differ by about 3 minutes per month.

    But because the clock on my cell phone is synchronized with "official" time on the interwebz, I just adjust them every few weeks.
     
  5. hbarcat

    hbarcat Supporting Member

    Aug 24, 2006
    Rochelle, Illinois
    I'm an industrial painter and I actually do need to know both temperature and humidity fairly accurately. But what I'm using now is adequate. But just barely.

    If I told my boss I needed a more accurate gauge, the company would just buy it for me. They trust my judgment.
     
    Last edited: Oct 4, 2022
    Old Garage-Bander likes this.
  6. dwm74

    dwm74

    Nov 8, 2009
    Phoenix, AZ
    I can sympathize. I'm diabetic, and supposed to check my blood sugar regularly. I'd been using one meter for several years then my doctor gave me another one. I decided to compare the readings between them. Every day it was a 10-30 pt swing in blood sugar readings, one would be higher for a few days then the other would be higher on occasion. Kept a spreadsheet to show my doctor the difference.

    The funny thing was, after 3 months worth of testing, the average of the two were almost identical (±2 pts). I guess for long-term data they were fine, but if I was in need of an 'accurate' reading for that particular day it was a crapshoot. :meh:
     
    hbarcat likes this.