Davis Vantage Pro2 Sensor Wackiness

[Blicj11]

I have recently had an interesting experience with my barometer. I used the quality control graphs on my CWOP account to check out my readings. My barometric pressure readings were high by an average of approximately 14 millibars. After watching this for several days and determining that my readings were consistently high, I decided to make a calibration setting adjustment in WeatherCat. This worked fine, but Steve suggested to me that if I made the adjustment in the Davis console itself, then my console and WeatherCat would show the same number. I entered the adjustment in the console, but almost immediately realised that I had accidentally entered the wrong number. I then cleared the barometer setting, which, on a Vanatage Pro, also clears the elevation. When I re-entered the elevation, the raw number for the barometer immediately adjusted itself to approximately 14 millibars lower than the previous readings. I decided to just watch it for a few days and see what happened. The raw pressure numbers appear to be much closer to where they ought to be compared to some known pressure readings at other stations in my area. The only fallout I have had from this is that WeatherCat registered 22 sensor errors for the barometer when the pressure dropped that far in such a short time when I was making these adjustments.

I made two conclusions.

• Sometimes, if you "blow the cobwebs out" of your console, it starts to give you more accurate readings
• Steve gives really good advice

[Bull Winkus]

I made two conclusions.

Sometimes, if you "blow the cobwebs out" of your console, it starts to give you more accurate readings
Steve gives really good advice

LOL! Well, you're probably right on both counts. I ran into issues with the pressure on mine as well. Long story short, after several months of poor quality evaluations from CWOP, I tried to adjust it in the console. It went wacky and dropped a lot, then later came back up. When I pulled up a custom graph with 1 year of anchored data for pressure, it was plain to see that it had been slowly trending over the last several months to a negative error. It was about an inch of mercury too low.

So, I ordered another one to replace the faulty one while sending it to Davis to be refurbished. On the day the new one arrived, while I was fiddling with it, the pressure corrected itself.

I went ahead and put the new one in service. I'm still trying to decide if I should send the old one back for recalibration and refurbishing.

I think the pressure sensor may have some sort of mechanical friction or hysteresis to overcome after a little house dust settles inside the console.

Herb

[elagache]

Hi Blick, Herb, and WeatherCat fans,

Hmm, interesting stuff.  I have noticed that my Weather Envoy has been drifting apart from my VP-2 console on barometric pressure.  I hadn't bothered to figure out exactly how much.  However, both devices are in a relatively dusty house and the dust has been worse because of the drought.  Perhaps indeed I should get out the air duster and see what that does.

Cheers, Edouard 

[Blicj11]

I think the pressure sensor may have some sort of mechanical friction or hysteresis to overcome after a little house dust settles inside the console.

Herb:

I never thought of that but I am inclined to agree with you. I think I will take my canned air to the console.  Hope I don't blow something off that should be on!

[Bull Winkus]

Careful, Blick! That canned air can pressure the sensor. ;-)

[Blicj11]

I will be very gentle.

[Steve]

I made two conclusions.

• Sometimes, if you "blow the cobwebs out" of your console, it starts to give you more accurate readings
• Steve gives really good advice

Thank you very much for the kind words, John! I'm glad it worked out OK.

Steve