Babu I thought you were using a sensor on an apartment balcony and was surprised it was so accurate. Now I know. This is a good set-up for a PWS in my opinion.
The response time of my sensor is rated at 228s (for 63% of a step change). I looked at studies made on official meteorological equipment, and apparently the typical mercury thermometer used to record instantaneous temperature in Australia has a 147s response time, and their mercury maximum thermometers have a 211s step change and their alcohol minimum thermometers have a 277s step change. So my PWS is actually very well in line with classical mercury thermometers when it comes to response time. The digital PRT sensors BOM use have a response time of 95s. It's unclear however if this is with or without a digital filter that averages the readings (for example, SMHI average the last minute of their readings for their automatic stations to more closely match the response time of mercury thermometers), but I presume that it isn't.
I changed the recording frequency to 1 minute. It means it will only be able to store data for a little less than a month, but I visit it more often than that to download the data anyway so it isn't really a problem. The 1 minute interval instead of 5 minute interval seems to allow it to record slightly warmer highs (0.1'C to 0.2'C); it seems to make a difference.
I seemed to have solved the issue where my station would over-read between 18.30-20.30. I put some dead pine branches in the spruce tree to the NW to make the vegetation/"foliage" denser in a natural looking way (my PWS is pretty much placed in the back garden of the county office building so I obviously don't want to draw any unwanted attention to it haha)
Post by flamingGalah on Jul 28, 2021 18:28:35 GMT -5
My new weather station arrived, it's a Fine Offset clone (same as Ambient, that are marketed under a few different names in Europe) this one was from Waldbeck in Germany. I have attached it to the trunk of a Cordyline as it's the only place in the garden where it will get sun pretty much all day (the station is solar powered & has UV/light sensor) & also will get better wind readings as it's up above the height of the fences/hedges. Going to wait until August to start keeping records from it, gives me a chance to see if anything needs calibrating over the next few days too.
Here's my PWS. Forgot to post it before, there you go:
^ Yea, I acknowledge it's not exactly the best placement (concrete is about 10 feet away; temps probably run a couple of degrees high in evenings where winds are from the east), but fine most days. Granted, I could've placed it further down the valley but then I'd be worried about overgrowth and such, I'll be moving out of here before the end of this year anyways.
Last Edit: Aug 15, 2021 11:49:19 GMT -5 by Benfxmth
"Above 40 degrees North, there is no Winter warmth; Above 50 degrees North, there is no Summer heat; Above 60 degrees North, there are no Thunderstorms; Above 70 degrees North, there is no Hope." — Benny Boy's adage.
Here's my PWS. Forgot to post it before, there you go:
^ Yea, I acknowledge it's not exactly the best placement (concrete is about 10 feet away; temps probably run a couple of degrees high in evenings where winds are from the east), but fine most days. Granted, I could've placed it further down the valley but then I'd be worried about overgrowth and such, I'll be moving out of here before the end of this year anyways.
I don't know how much concrete there is 10ft away, but to me the biggest problem with the placement is the excessive vegetation underneath and around the station, as well as being located on a rather steep slope. I'm assuming your station is also actively aspirated? Compared to a typical WMO station I'd assume your station to record noticably milder lows, as well as highs that are consistently cool, sometimes by as much as a couple degrees (depending on what location you compare it to of course).
Here's my PWS. Forgot to post it before, there you go:
^ Yea, I acknowledge it's not exactly the best placement (concrete is about 10 feet away; temps probably run a couple of degrees high in evenings where winds are from the east), but fine most days. Granted, I could've placed it further down the valley but then I'd be worried about overgrowth and such, I'll be moving out of here before the end of this year anyways.
I don't know how much concrete there is 10ft away, but to me the biggest problem with the placement is the excessive vegetation underneath and around the station, as well as being located on a rather steep slope. I'm assuming your station is also actively aspirated? Compared to a typical WMO station I'd assume your station to record noticably milder lows, as well as highs that are consistently cool, sometimes by as much as a couple degrees (depending on what location you compare it to of course).
That's a good point, I noticed that compared to other nearby PWSes it records highs 1-2°F cooler when winds are from S/SW/W/NW (not so much the case when winds are light, usually similar). It's passively aspirated, and usually records similar lows comared to other PWSes near me, though.
"Above 40 degrees North, there is no Winter warmth; Above 50 degrees North, there is no Summer heat; Above 60 degrees North, there are no Thunderstorms; Above 70 degrees North, there is no Hope." — Benny Boy's adage.
With any luck, Adi From the Poopsticks is not being serious. With any luck.
20th Century: White Australia Policy 21st Century: Yellow Australia Policy
I have a very hard time believing your stool would have a higher alcohol content than your blood; if it were so, you'd get drunk off of your own shit inside your rectum - Babu 2021
@frozeniq69 That's just a standard fare thermo-hygrometer, and not a PWS, you fuckwit.
"Above 40 degrees North, there is no Winter warmth; Above 50 degrees North, there is no Summer heat; Above 60 degrees North, there are no Thunderstorms; Above 70 degrees North, there is no Hope." — Benny Boy's adage.
I ended up relocating my PWS last night further down the backyard because I didn't like the proximity to pavement/concrete with the previous setup (was fucking stupid for not doing that earlier), especially when it's closer to PWS height than the mean height of it (made for overly warm readings during the day when winds are from the east):
Last Edit: Oct 23, 2021 3:53:31 GMT -5 by Benfxmth
"Above 40 degrees North, there is no Winter warmth; Above 50 degrees North, there is no Summer heat; Above 60 degrees North, there are no Thunderstorms; Above 70 degrees North, there is no Hope." — Benny Boy's adage.
Working on a new project, an external temperature sensor for a car. My current car doesn't have one and I've been really missing that feature, so I decided to build one that should hopefully be a lot more accurate than the typical sensor mounted right in front of the radiator.
I managed to pick up a sensor and display from Ebay for only $12. It uses a DS18B20 digital sensor, which is rated for ±0.2 °C accuracy between 10 °C and 40 °C and ±0.5 °C accuracy outside of the range. I checked it against a certified NIST-traceable thermometer and the two agreed within 0.1 °F, so I'm pretty impressed considering the price. It runs on 12V, so I can easily plug into the outlet in my car. The nice thing about the display is it's not some annoying battery powered thing with a LCD screen that shuts off after a few seconds. This LED display will be bright and visible at all times.
I'm sure there will still be lots of heat from the road raising the temperature, but mounting it at a more typical height with plenty of airflow should help mitigate that issue as much as possible. I've designed a radiation shield to house the sensor and a mount that quickly clamps onto the side mirror. Still in fabrication phase, but I should be able to have it up and running within a week or two.
Working on a new project, an external temperature sensor for a car. My current car doesn't have one and I've been really missing that feature, so I decided to build one that should hopefully be a lot more accurate than the typical sensor mounted right in front of the radiator.
I managed to pick up a sensor and display from Ebay for only $12. It uses a DS18B20 digital sensor, which is rated for ±0.2 °C accuracy between 10 °C and 40 °C and ±0.5 °C accuracy outside of the range. I checked it against a certified NIST-traceable thermometer and the two agreed within 0.1 °F, so I'm pretty impressed considering the price. It runs on 12V, so I can easily plug into the outlet in my car. The nice thing about the display is it's not some annoying battery powered thing with a LCD screen that shuts off after a few seconds. This LED display will be bright and visible at all times.
I'm sure there will still be lots of heat from the road raising the temperature, but mounting it at a more typical height with plenty of airflow should help mitigate that issue as much as possible. I've designed a radiation shield to house the sensor and a mount that quickly clamps onto the side mirror. Still in fabrication phase, but I should be able to have it up and running within a week or two.
The external temperature reader on my car is almost completely defective, in the unlikely event that you ever reply to one of my posts do you have an idea on how it could be fixed? I've tried asking about it on a forum for my car brand but they weren't helpful.
3D model of the sensor mount design. I decided to abandon the mirror mount design and go for something a bit more secure. My car has an antenna mount held on by two screws just above the driver side door. If I replace these screws with male to female standoffs, I can quickly detach the sensor mount with wing screws. The antenna mount is oriented at a difficult to measure angle, so I have an adjustable clamping ball mount in the part to allow for leveling the shield. One caveat is the sensor cable has to pass through the door, but the door seal seems to conform to the shape of the cable with the door closed just fine so I'm not too worried.
It has a few advantages over the mirror mount. It's about a foot higher so there will less affect from the road surface and it also doesn't block my visibility. I'd like to go even higher (around 6 ft) but the sensor cable isn't long enough for that.
Sensor mount as printed. Briefly tested it out tonight and it worked great. I was a bit worried the sensor would be too slow to measure small localized variations in temp, but it's incredible how much faster the response is in moving air compared to still air. It settled at ambient temp only a couple seconds after moving.
Will be adding a coat of white paint to better reflect sunlight.
Painted and mounted. Sorry for shitty night photo but I haven't had any time to test it during the day. I just got it finished today and went on a 20 mile test drive. Worked flawlessly, very interesting to see the cool and warm spots on a calm clear night like tonight. When I drove over a tall bridge over a canal, the temp rose by 4 F. And when I got back to my driveway, it was reading exactly the same as my PWS in the backyard, to 0.1 F precision. I'm very pleased with the result.
Lived:
Residence:
