The heating rate in setting

yingzhen
New Member

Posts: 5

The heating rate in setting Aug 25, 2021 3:14:46 GMT -5

Quote

Post by yingzhen on Aug 25, 2021 3:14:46 GMT -5

Dear Engineer,

Hi, this is National Pingtung University (NPTU), Department of Applied physics. There have some question about the heating rate in setting.
Our instrument is High temperature oven 74034 and temperature controller is 336.
For the temperature control setting we use the domains same as the manual.
But the measuring time per one time is too long for us. When we measure the temperature 30-600°C it spend 8-9 hrs.
According to the raw data, the heating rate around 1°C/mins. In this case, did it have any factor or setting can change or modify.
We hope the rate can increase to 4°C/mins even 10°C/mins.

All the best for you,

Alice

Lake Shore Cosmin
Lake Shore

Posts: 22

The heating rate in setting Aug 25, 2021 13:14:46 GMT -5 yingzhen likes this

Quote

Post by Lake Shore Cosmin on Aug 25, 2021 13:14:46 GMT -5

Dear Ying Zhen,

Because the VSM oven heats the sample mostly by radiation and by conduction (no convection) it is inherently slow, in order to allow sample temperature to follow the sensor temperature. The default parameters will ensure compliance with temperature accuracy specs.
If you can accept an increased mismatch between sample temperature and readings, you can edit the temperature domains for your specific measurement. You would want to decrease the "settle time" and increase the "settle band" in addition to increasing the ramp rate you've already tried. For example you can use "settle time = 0.1min" and increase the "settle band = 5C", etc.

The concept of modifying a domain to increase speed is extremely useful also for field when you measuring FORC.

Please address these type of enquiries to service@lakeshore.com for a faster response.

Thank you,
Dr. Cosmin Radu

yingzhen
New Member

Posts: 5

The heating rate in setting Sept 1, 2021 2:37:46 GMT -5

Quote

Post by yingzhen on Sept 1, 2021 2:37:46 GMT -5

Dear Engineer,

There has another question about the heating rate in the setting.
For the temperature control setting, the heating rate is around 1°C/mins.
If we change the ramp rate in the domain setting, how does maximum the heating rate it can work?
I write the email to service@lakeshore.com but didn't have the answer.

All the best for you,

Alice

Lake Shore Cosmin
Lake Shore

Posts: 22

The heating rate in setting Sept 1, 2021 10:25:38 GMT -5

Quote

Post by Lake Shore Cosmin on Sept 1, 2021 10:25:38 GMT -5

Dear Alice,
In my previous reply I mentioned temperature domains adjustments – settle band and settle time. Did you try that?
The VSM oven can ramp as fast as 10 deg/min but depending on the sample size and mounting, its thermal inertia may lead to a lag of the sample temperature behind the indicated temperature.

You can always set the ramp rate in domains to 10 deg/min. The settle band and settle time are the determining factors for oven speed.

Thank you,
Dr. Cosmin Radu