temp measurement for SCT's - yes, I finally succumbed

[Robert_T]

Hi Guys, finally succumbed and bought myself an indoor/outdoor temp sensor from DSE - I got the one with relative humidity measure - not sure if this will be of any use, just interested.

I was just going to rest the sensor inside the baffle tube toward the end with the main unit stuch to the pier. Any other suggestions on this, hw you guys use these?

cheers,

[matt]

Rob

The humidity sensor might be handy for gauging whether dew will be an issue for your corrector.

Are you suggesting sliding the outdoor sensor inside the baffle until it's dangling inside the OTA? That'll give you the temp inside the tube but not the primary mirror temp which is what you really want.

Still more useful than not having any temp readings at all, I guess

[Robert_T]

Originally Posted by matt

Rob

The humidity sensor might be handy for gauging whether dew will be an issue for your corrector.

Are you suggesting sliding the outdoor sensor inside the baffle until it's dangling inside the OTA? That'll give you the temp inside the tube but not the primary mirror temp which is what you really want.

Still more useful than not having any temp readings at all, I guess

good idea on the humidity sensor! yeh, just slipping the outdoor sensor down the baffle, not the same as measuring the primary mirror, but my theory is that is the air in the tube isn't ambient then there's no chance the mirror will be. should at least tell me when there is definitely a temp imbalance if not when there isn't.

[asimov (John)]

Tinkerer & scope stripper here!

Itching to get that sensor on that primary, plus mirror lock plus flocking plus re-grease of baffle tube plus active cooling!!

Why have I not done it yet? It's still under warranty!

Nice idea Rob. It will give you some indication of whats going on for sure

[Hitchhiker]

Hi Robert_T, I built my own SCT Cooler from PVC pipe parts and a computer fan. I had a DSE indoor/outdoor temperature sensor so I stuck one of the sensors on the end of the tube. Here's a picture I posted earlier (you can just see the sensor on the end of the long PVC pipe):

http://www.iceinspace.com.au/forum/a...3&d=1148696921

Now, after having used it a while, you can certainly tell when the air inside the tube is at ambient, but not much else. I just leave the cooler in for at least an hour and a half and assume the mirror gets to ambient. Sensors on the mirror would be better, though, and, if I ever have to disassemble my scope for any reason, I will put some on.

[Robert_T]

thanks Adam, that's a good idea sticking the sensor on the end of the cat-cooler - I've got a commercial version so I will do the same.

[Shawn]

Hey Adam, thats a neat device you made there, how does it work, blow suck ?, and where does the replacement air go to or come from, and is it filtered, I have wild temp differential here..


Cheers shawn

[Hitchhiker]

Hi shawn, I used a DSE computer fan to blow air up into the OTA through the PVC pipe. I have a filter on the intake end. Here are some links to sites on the web that descrbe how to make a DIY cat cooler.

http://members.tripod.com/tom_shaull...ope_cooler.htm

http://www.starcrwzr.com/cooler.htm

I just went to Bunnings and got PVC parts that would fit together for the tube. I've got an exploded view of all the parts somewhere - I'll post it when I can find it!