Min Max Thermometers

[peanut]

Can anyone recommend a min mix thermometer please?
Plus...
Will my glass greenhouse be warmer than my Aldi plastic greenhouse? They are the same size and similar positions.
And...
How much warmer will it be inside an unheated propagator placed inside either greenhouse?

Thank you

[burnie]

That's an almost "how long is a piece of string question" A glass house will be warmer and more importantly it will let in more light than plastic. I have tried measuring temperatures with a max/min temp inside props, not convinced with the results, but as with all temperature measurements, prevailing conditions make a huge difference, is it sheltered spot, do you get sun all day, how far north are you?
My thermometer is a Garman, fitted with a digital readout along with a traditional tube, bought as a gift for me, it has been running for almost 2 years on the current batteries.

[peanut]

That's an almost "how long is a piece of string question" A glass house will be warmer and more importantly it will let in more light than plastic. I have tried measuring temperatures with a max/min temp inside props, not convinced with the results, but as with all temperature measurements, prevailing conditions make a huge difference, is it sheltered spot, do you get sun all day, how far north are you?
My thermometer is a Garman, fitted with a digital readout along with a traditional tube, bought as a gift for me, it has been running for almost 2 years on the current batteries.

Yes it is isn't it!
It's good to have impossible questions to ponder over every now and again

[burnie]

He-he, I guess you will be experimenting on all of our behalves, I await your scientific results with curiosity and trepidation lol.

[quanglewangle]

It's important to shield the thermometer, at least the bulb part, from the sun and to let air circulate around it. Something like an offcut of insulation board with the instrument mounted on the North side.

Propagator will warm up in sunshine then cool at night. Again insulation board helps. My propagators stand on 50mm polyurethane batts.

FYI
Graphs show temperatures for air, ground bed, and propagator. Propagator and ground are heated tp 20°C but you can see the effect of some sun this morning.

[edit] outside temp was steady 9°C throughout.

[peanut]

Thanks quanglewangle I will bring the propagators in overnight and put them out in the day so they get good daylight.

[Snoop Puss]

It's important to shield the thermometer, at least the bulb part, from the sun and to let air circulate around it. Something like an offcut of insulation board with the instrument mounted on the North side.

Propagator will warm up in sunshine then cool at night. Again insulation board helps. My propagators stand on 50mm polyurethane batts.

FYI
Graphs show temperatures for air, ground bed, and propagator. Propagator and ground are heated tp 20°C but you can see the effect of some sun this morning.

[edit] outside temp was steady 9°C throughout.

Brillant, QW. I knew you'd be along with a graph. Interesting to see there's still a temperature difference at night. I just assumed temps would end up more or less the same at night, but evidently enough warmth absorbed during the day to provide some protection. Good question, peanut.

[quanglewangle]

I knew you'd be along with a graph. Interesting to see there's still a temperature difference at night. I just assumed temps would end up more or less the same at night, but evidently enough warmth absorbed during the day to provide some protection.

Actually Snoop, not quite... The propagator and ground bed are heated. Were they not I am sure your assumption would be true. The sensor will turn the cable off at 20°C but the 120W cable isn't powerful enough to get them up to that in the unheated greenhouse.

Although I don't bother now we have 9°C nights, I was covering both propagator and bed with fleece when we had a run of 1-2°C nights earlier and that makes 2-3°C difference.

[Snoop Puss]

^Ah, that explains it.

9 ºC nights. That's positively balmy. We're still in the minuses most nights here...

[peanut]

I've made a bit of a rookie error, as I liked my first indoor/outdoor min/max thermometer so much I bought a second one for my Aldi NeverGoingToBlowAway.
The problem is that they both connect to the same outdoor sensor.
If I buy a different make will I have the same problem?

I don't know what to do!

[Plot70]

Have a look on the web and see if one of your units can be altered to use a different channel to link to the indoor part.

[peanut]

Have a look on the web and see if one of your units can be altered to use a different channel to link to the indoor part.

It doesn't have any options for alternative channels.

[Plot70]

It must be a cheap unit then.

[Eoghan]

I use a remote sensor which I can read in the kitchen