demorol
Harmless
Posts: 7
Registered: 13-2-2005
Member Is Offline
Mood: No Mood
|
|
Thermometer question
I have recently aquired new thermometer for the distillation setup and I realized I have probably bought the wrong one. On the back of it says
"total immersion", so I suppose it must be immersed in the liquid you are heating, which means it is useless for distilling purposes. Then I
looked in the glassware catalog and realized there's no such thing as "distillation thermometer". All I could see was a variety of
different thermometers with immersion depth ranging from 50 to 108 mm. I'm puzzled, because I don't know which one to get, and I certainly
don't want to be spending any more money on useless "total immersion" thermometers. Should I get the one with the lowest immersion
depth? I'd be very grateful if anyone can help me with anykind of answer.
I don't know if said it already, but the thermometer is needed for distillation.
Thanks.
[Edited on 13-2-2005 by demorol]
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
I think 75mm immersion is pretty standard. It's what we used at school and what I bought for home use.
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
mycoguy
Harmless
Posts: 12
Registered: 7-1-2005
Member Is Offline
Mood: No Mood
|
|
yup, you need a PI thermo. 76mm immersion is common.
|
|
|
demorol
Harmless
Posts: 7
Registered: 13-2-2005
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by mycoguy
yup, you need a PI thermo. 76mm immersion is common. |
Thank you all. Just one more question, as I'm new here. What does PI mean?
|
|
|
neutrino
International Hazard
Posts: 1583
Registered: 20-8-2004
Location: USA
Member Is Offline
Mood: oscillating
|
|
Partial immersion. It’s the type that only needs to be immersed to a certain line on the thermometer.
|
|
|
demorol
Harmless
Posts: 7
Registered: 13-2-2005
Member Is Offline
Mood: No Mood
|
|
I still don't get it. So "76 mm immersion" means that you actually have to immerse the thermometer into liquid for 76 mm? If so, how
are you gonna read the distillation temperature?
Thanks!
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
76mm is the immersion to which the thermometer is calibrated. That's the optimum immersion. It will still give useful readings with other
immersions. But the closer to 76mm the more accuracy you get.
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
