Increase cool down segment time

The sample cool down time will be some maximum rate determined by the environment.   What I'm saying, is if the TGA does not have an active cooling system (such as water jacket or something like that) it will only cool down based on the temperature of the surroundings and air circulation.

I use a technique that offers no value for data collection, but I end the cycle after my experiment in the software, then add a step for cool down at 20°C per minute which will give an extended time to finishing the experiment.   I noticed that this negative ramp rate works well at 1000 to about 500° when compared to room temperature, but it is less consistent as it cools as I have not seen a TGA with a cooling system, althought I am told they exist.   At leaset adding a negative ramp to the end of the experiment will give you an approximate finish time, which is what I use it for, but it has no value for data.

If you are in a hurry, you could use air cooling (most instruments should have this) but also, this will not be a guaranteed ramp rate.  Keep in mind whatever ramp rate you select the instrument will try to meet that ramp rate, so if you do 50° per minute or higher, you might damage components because it is not capable of that ramp rate.    I know the new discovery series can go 20° per minute positive, and with the furnace closed, it's unlikely you can go faster in the negative direction without active cooling.

Hi.

Witch model TGA do have (Q 50, q 500 ect..) ? Does your TGA have an EGA furnace ?

Here is where you can contact me 530-867-5519 0r brivas@rtinstruments.com

Hi 

I am not sure you are addressing me, as this post is about three  years old, and I just posted to it three days ago.  The unit is controlled by software.   Having had training by the folks at TA instruments on a newly purchased setup we had at my last job, and a few years of working with these instruments, without an active cooling system there is no way to accurately ramp the TGA down, we can only give it our best shot with reducing the furnace power or air cooling (or a little of both).

I use my technique not for experimental purposes, but for timing. If I run several samples, the software will tell me approximately when it will be done, so I can set my alarm to remind me to come back to lab and check on it, so I can free up the TGA and cleanup for other users.    This forum would not permit me to edit my post, so I could not change it.   The post talks about lengthening the time not shortening the time between samples.  

My method should work for that even better.  The instrument will attempt to ramp down at a pre-set rate, but without a supplemental cooling system, it will only marginally work.  Normally people want to shorten, not extend, the time between samples, so this should be easier to accomplish than trying to set a shorter time period between each sample.