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TC-08 Sampling Rate

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TC-08 Sampling Rate

Postby MKane » Thu Jul 14, 2011 9:59 pm

Hi, I've been using a USB TC-08 to track 6channels of thermal data. I just need a 20 second total observation interval, but I'd like 10Hz sampling rate or better per channel. I've just downloaded the latest data logger version, and I can specify what I want in the setup, but the resulting data file doesn't actually update at 10Hz/ch. Instead, it will repeat one value several times until an updated value is available. So I get 200 data points per channel using 10Hz, but the actual update rate is closer to 1 or 2 Hz.

The software will not allow me to select any mode other than real-time-continuous, a name that seems at odds with data rate I'm observing.

Changing the channel count does increase the update rate. So enabling 6 channels allows updates at about
1.25Hz and enabling only 2 channels updates at about 3 Hz.

Once upon a time in the beginning of using this software, I thought I was acquiring data much faster. But I've either lost the recipe, or I'm delusional about my youth. Is the slow update rate a limitation of the acquisition system or the operator? Can someone lend some insight?

thanks very much
Michael
MKane
 

Re: TC-08 Sampling Rate

Postby ziko » Thu Jul 21, 2011 10:57 am

Hi Michael,

The USB TC-08 has a conversion time of 100ms for the ADC, there is a multiplexor there that scans through the channels and the cold junction, so for one channel you will get 200ms, for 2 channels you will get 300ms and so on, for all channels it will be approximately 1 second taking into account the overheads as well.

Real time continious is the only mode that you can use for the TC-08 as it is a slow sampling device the other modes are really for the faster data loggers or scopes.

Kind regards
Ziko

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