Choosing DAQ for pressure and thermocouple

[vepa]

What PC connected DAQ system would recommend for connecting this pressure sensor: https://www.te.com/usa-en/product-U5244-000005-030PA.html? I am looking at USB DAQs and am not sure if I can do a plug and play with this sensor or I will need some sort of signal conditioning.

Also, if the DAQ has ports for connecting thermocouples directly without any signal conditioning that is the ideal DAQ I am looking for. Sampling rate of anything above 1KS/s is good. I need at least 12 digital I/O for powering the sensors (I don't know if any DAQ can output between 8-30V which is requirement for pressure sensor). I will be connecting 3 pressure sensors and 3 thermocouples.

[hypeee]

Hello,

My situation is simple. I get the pressure from a pressure sensor.

It returns 0...10 V for a -1...6 bar pressure

I just open the DAQ assistant (input => voltage) and returns the value. I set Continuous Values because I want to have the continous values. I set 100 Hz because I don't need so much values every second (and also 1000 Hz bug).

It works 100% fine.

Problem is : it's not calibrated perfectly. So I use the calibration. I have small differences. I attached the picture. But when I use the calibration I have the error (image attached). If I unclick "enable calibration" (meaning desactive it), it works.

I set from 0 to 10 V, what my sensor delivers.

Any idea what this is ? "specified value is smaller than the minimum value" "corresponding value : 10"

doesn't make any sense to me.... thanks so much if someone can help !!

[vepa]

Can you make this a new thread? Don't know why you replied to my question as not relating to my question

[santo_13]

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@vepa wrote:

What PC connected DAQ system would recommend for connecting this pressure sensor: https://www.te.com/usa-en/product-U5244-000005-030PA.html? I am looking at USB DAQs and am not sure if I can do a plug and play with this sensor or I will need some sort of signal conditioning.

Also, if the DAQ has ports for connecting thermocouples directly without any signal conditioning that is the ideal DAQ I am looking for. Sampling rate of anything above 1KS/s is good. I need at least 12 digital I/O for powering the sensors (I don't know if any DAQ can output between 8-30V which is requirement for pressure sensor). I will be connecting 3 pressure sensors and 3 thermocouples.

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There are a bunch of options for USB DAQs. 

1. Yes, there are thermocouple DAQs where you just plug-in thermocouples. The sampling rate for Thermocouple DAQs are usually <100 samples per second, it is logically not possible for the thermocouple to react faster than 10ms and moreover to get a higher resolution sampling rate has to be low. So, the sampling rate of 1kS/s for thermocouples are not logical.
2. You mention digital I/O, typically used to control relays or implement some sort of digital communication, why use it to power a sensor and why not get a power supply?
3. Typically, any DAQ dealing with high voltage will not drive the voltage but rather take in an external power supply and control it.

Based on your requirements, you're better off with a 4/8-slot cDAQ chassis.

Do you've any budget?

[vepa]

1. Makes sense for thermocouples, but I ideally want a plug and play for pressure too (and sorry I meant to say anything below 1kS/s so 100S/s is fine for both pressure and temperature), is that available? If not, what external circuitry would I need for the pressure sensor provided with 1-5V out?

2. I wanted it so I won't need an external supply and makes the setup that much cleaner. But if it is not an option then I will just buy an external supply.

My budget is under $1000

[santo_13]

1-5V signals are typically supported by almost all DAQs. It would be best to go with an external supply.

Your budget is a bit too tight to get a proper DAQ system that can support 3 TCs, 3 pressure sensors(1-5V), 12 DIO. If you will get an external signal conditioning for TC that in turn outputs 0-5V or 0-10V, you could fit some DAQ in your budget.

Please share more about the use of DIO, voltage levels, current drive capability, does it require any waveform generation ability?

[vepa]

Well with the $1000 budget how many sensors can I connect in DAQ not requiring external signal conditioning. I am ok going above $1000 is ideal value.

The main use of DIO was for powering sensors so seems like the DAQ can't give the power required for powering pressure sensors, so a 5V dc out is good enough for powering relays that I will also be using to control other equipment. Current drive of anything up to 500mA is good.

[santo_13]

Still, your $1000 budget is insufficient for your requirements.

Any digital output capable of driving more than 10-15mA will become a power supply, so, no, there is no digital input/output that can drive 500mA without an external supply.

Let us take USB-6003 ($600) and analyze fit for your requirements

• Measure TC?
  • Needs external amplifier to convert Temperature to 0-5V or 0-10V signal
• Measure sensors 0-5V
  • 4 differential or 8 single-ended signals supported
  • Fixed +/-10V 16-bit Analog input with typical accuracy 7mV (26mV worst case)
• Control external relays
  • 13 DIO lines
  • 5V compatible inputs
  • 3.3V capable output or open-collector output (sink/source up to 4mA)
  • Needs external power supply and relay drivers to control relays

Now, you could observe why the <$1000 low-cost DAQ cannot fit your requirements without a lot of external circuit components.

Just a USB 4Ch 14S/s Thermocouple DAQ costs $800 (directly plugin the TC) - https://www.ni.com/en-us/shop/hardware/products/usb-temperature-measurement-bundle.html

USB-6525 ($400) is a good 8ch DI and 8ch DO for industrial use up to 60V (with external supply) and control 500mA loads using the SSR on DO channel - https://www.ni.com/pdf/manuals/371818b.pdf

[santo_13]

If your budget is tight, give it a try on https://www.mccdaq.com/ - they got some low cost DAQs

[vepa]

What are the options available if I had a higher budget say $3000?