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ADC-11/12 Inputs

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ADC-11/12 Inputs

Postby peplow » Wed Nov 12, 2008 11:33 am

Hi all, new to the site so forgive me for any questions that is child's play

My first question is I want to know exactly what input types can be used and is it only voltages that are allowed?

Secondly, will the ADC-11/12 allow K type thermocouples to be connected directly to it or will I need a TC-08 for any temperature measurement?

If I do need the TC-08 along side the ADC-11/12, can they both be run at the same time, on the same PC, on the same PicoLog graph?

If not, can I run each device on the same PC but have a PicoLog graph open for each device so I would end up with two graphs open, one for voltage measurement and one for temperature?

Many thanks in advance

Mitch
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Postby PeterF » Wed Nov 12, 2008 11:52 am

Hi,
The ADC-11 inputs are rated 0V to +2.5V but if you put 120 ohms in parallel with the input then a 4-20mA sensor will generate from 480mV to 2.4V across the resistor and this voltage will be logged. Scaling can be adjusted to read in the correct units.
Thermocouples cannot be directly connected, you would need to use a "Cold junction compensation" circuit for each one (details given in the terminal board manual).
Multiple loggers can be connected at the same time to one instance of PicoLog and all readings can be displayed and saved at the same time. Only one instance of PicoLog can run at a time.
Regards,
PeterF.
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Postby peplow » Wed Nov 12, 2008 12:40 pm

You are a start PeterF, exactly what I needed to know

It will be easier and less time consuming for me to buy the ADC-11 and the TC-08, unless the CJC circuit is just a couple of components?

Pico do not produce a CJC input extension board then I take it?

Thanks again for the help

Mitch
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Postby PeterF » Wed Nov 12, 2008 1:17 pm

Hi,
The CJC circuit is built round a special I/C. We don't make any interface for it ourselves. It might be useful if you only wanted one thermocouple but more than that would be a pain!
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Postby peplow » Wed Nov 12, 2008 1:59 pm

Think I will buy a TC-08 : )

Cheers Peter

Mitch
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Postby peplow » Thu Nov 13, 2008 3:45 pm

Just another quick question

The max input voltage is +2.5V DC but does this mean 2.5V is the maximum range limit or the maximum safe working limit?

Basically I have a signal conditioner that kicks out 0-5V so if the ADC-11 saw 5V on ther input terminals, would it destroy the unit or just saturate the signal?

Many thanks

Mitch
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Postby PeterF » Thu Nov 13, 2008 4:55 pm

Hi,
With +5V the input would just saturate. It is protected to +/- 30V.
Regards,
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Postby peplow » Fri Nov 14, 2008 7:35 am

Excellent news, cheers Peter
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