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TC-08 reading

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TC-08 reading

Postby aragonroller » Wed Feb 02, 2011 11:24 am

I would like to ask that the indicated 10 readings per sec is defined to overall the whole device, or per one plug.
aragonroller
 

Re: TC-08 reading

Postby ziko » Thu Feb 03, 2011 6:56 pm

Hi,

Each device will be able to do 1 second for all 8 channels, so if you had multiple devices the time would still be 1 second. To explain this in more detail each device has one ADC and a multiplexor to switch between channels and this is why the time is spread across the channels of a single unit.

Kind regards
Ziko

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Re: TC-08 reading

Postby aragonroller » Fri Feb 04, 2011 10:36 am

I would like to only use one device and two channels. Is it possible to read for example 5 data per second on each channel?
aragonroller
 

Re: TC-08 reading

Postby ziko » Fri Feb 04, 2011 12:39 pm

Hi to be specific about how each USB TC-08 works the conversion time of the ADC is 100ms so this is per channel, you also have the cold junction to take into account.

So for 2 channels this is 200ms + 100ms for the cold junction. So it would be approximately 300ms.

Hope this helps.
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Re: TC-08 reading

Postby aragonroller » Mon Feb 07, 2011 1:50 pm

So in case of using two channels, 3readings/sec/channel is only available?
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Re: TC-08 reading

Postby ziko » Tue Feb 08, 2011 12:17 pm

Yes that is correct.
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Re: TC-08 reading

Postby tmj » Mon Jun 13, 2011 11:50 pm

I am a new user of the TC-08. The system I was previously using was able to sample at ten samples per sec. (10Hz) for two channels, for an aggregate rate of 20Hz.

When I try to run that fast on the TC-08 I get a lot of what seems to be “clipped” data. I have to back the sampling rate off considerably to get smooth looking data.

Did I misinterpret the sampling capacity of the TC-08? Is the 10Hz rate for the whole module (aggregate), and not an individual channel? And even if I am not using all channels, how does it divide up the sampling capacity?

If I want to use two channels with no CJ. I am limited to a maximum sampling rate of what……….?

Thanks for helping clear up my confusion.
tmj
 

Re: TC-08 reading

Postby olepagh » Wed Jun 15, 2011 3:30 am

tmj wrote:If I want to use two channels with no CJ. I am limited to a maximum sampling rate of what……….?


You cannot measure temperatures with a thermocouple without a Cold Junction compensation.
That is a fundamental of thermocouple theory, as you actually measures a voltage difference betveen at least two TC points.
Google search for "Thermocouple theory" A top hit is:
http://www.efunda.com/designstandards/s ... theory.cfm
/ Best regards
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