Fast temperature recorder

[Swaroop]

Hello,

We are currently working on a water chilled copper mold, into which molten Aluminum is poured at around 800C [~ 1500 F]. We would like to measure the cooling rate (rate of change in temperature) of the alloy as it solidifies. 

 

The issue we are facing with our current temperature recorder system is that the system is too slow to record the temperature change in real time. The mold pulls the heat from the melt at an incredible rate and we assume that the cooling rate is in the order of 1000 K/s. While we pour the melt at 800C, the first temp that the temperature recorder shows us is around 500C, because the response rate is not fast enough. The thermocouple needs a few seconds to stabilize at a given temperature - but in that period the alloy has already solidified. 

 

We have tried using very fine thermocouples (K-type) (0.38 mm) for quick response. We are using MCC USB-2408-2AO which on paper could record at 1000 Hz, but the noise beyond 5 Hz is higher than the signal. Maybe I ma unsure of the correct settings to use this device.

 

I am reaching out to find out if there are any setups available that could solve our problem. Looking forward to hear from you.

[Fausto]

Hello @Swaroop.

The USB-2408-2AO has a maximum aggregate analog input throughput rate of 1,100 samples/sec.  However, for thermocouple temperature measurements, the A/D data rate should be set to 60 Hz, in InstaCal, to help with noise filtering.  This rate is less than your application's requirement.

 

The only other option available from Digilent for higher sampling rates is the legacy daq device DT9806.  A maximum aggregate sampling rate for temperature measurements is 10,000 samples/sec.

https://files.digilent.com/datasheets/DT9805-DT9806-Datasheet.pdf

https://files.digilent.com/manuals/UM9800.pdf

 

Regards,

Fausto

[Swaroop]

Thank you for your quick reply, Fausto.

I have two questions regarding the instrumentation. 

1. What thermocouples can be used with the daq device DT9806? Will a K-type work, and what would be the limiting factor in the thermocouple, if any? 

2. In order to make the connections between the thermocouple and the daq, are there any training videos, other than the manual?

3. For the USB-2408 that we already have, I use the DAQAMI software. Is InstaCal a separate software that needs to be purchased or does it come free with the purchase of the device?

[Fausto]

On 9/30/2024 at 11:31 AM, Swaroop said:

What thermocouples can be used with the daq device DT9806?

https://files.digilent.com/manuals/UM9800.pdf

 

On 9/30/2024 at 11:31 AM, Swaroop said:

In order to make the connections between the thermocouple and the daq, are there any training videos, other than the manual?

Two wire terminal connections on the DT9806 as mentioned in the user's manual.  Analog input channel 0 is left open and dedicated to the CJC.  Connect thermocouples to analog input channels 1 through 7 beginning with channel 1 for the first thermocouple.

 

On 9/30/2024 at 11:31 AM, Swaroop said:

For the USB-2408 that we already have, I use the DAQAMI software. Is InstaCal a separate software that needs to be purchased or does it come free with the purchase of the device?

Both DAQami and InstaCal software are free.

 

Regards,

Fausto