Temperature and humidity measurements

[Travis444]

Hi all, 

First off I am new to data acquisition and I would like to apologise in advance for any lack of knowledge, also if I am posting in the incorrect discussion board. 

I need help in selecting a data logger, preferably an 8 channel data logger, as well as the senors. I need to measure both temperature and humidity. I would like to have four temperature sensors and four humidity sensors and connect them to one 8 channel data logger.

From searching on this site I see that the NI 9201 is an 8 channel data logger but it is a voltage module and from what I have researched a thermcouples output won't match that modules input but on the other hand the humidity probes have voltage outputs. I have seen temperature sensors that have voltage outputs but they require additional components. So could the NI 9201 work for this application? 

This is for my final year mech. eng. project where a group of us have to build and test a solar dryer, since it is a student project the funding is small hence cost is a big factor. Essentially I just need help with selecting an 8 channel data logger with four temperature sensors and four humidity sensors, any help would be greatly appreciated

Thank you. 

[Astromaut · Accepted solution]

Hi Travis444

The 9201 looks like a good option for this application but the selection of the data acquisition devices strongly depends on the specifications of the sensors that you will use.

There are voltage input modules that can acquire from both type of sensors you are planning to use but they require the implementation of custom scales to do it. If you consider using a temperature module, you will avoid the usage of this scales and also you will win more accuracy on the temperature measurements.

Here you can find some Temperature Input Modules

The NI 9201 and the modules from the link above are c series modules that require a chassis to work. Here are some options.

Depending on your sensors, you could also consider using a USB Data Acquisition Device like the USB 6008

Feel free to contact National Instruments Sales Engineering Department at (877) 387-0015. They will be happy to help you looking for more options.

Regards

[Travis444]

Thank you for the help. I am interested in the USB 6008 and will contact NI for more information on it. Perhaps you could help me in the mean time. I have found some sensors I could possibly use here, they measure both temperature and humidity with a voltage ouput and an analogue interafce type but I am uncertain if I would be able to use them with the USB 6008 because they aren't NI sensors. I have found NI temperature sensors I could use but can you suggest any humidity sensors I could possibly use? 

Further, I am a bit uncertain on how the USB 6008 will work. Could I simply connect the sensors directly to the USB 6008 and then connect the USB 6008 to my laptop and with the relevant software be able to log the measurements directly as temperature and humidities? or would I need further hardware other than the sensors and the USB 6008? 

Kind Regards 

[Astromaut]

You are welcome. You can use any type of sensors from different companies by choosing the correct hardware for them. I was taking a look at your sensor and I think the USB 6008 can provide the excitation it requires but you can also use external excitation. Nevertheless, there are other devices and platforms that could work better for you. You can compare the specifications of the 6008 with your sensor's specifications and see if it meets all the requirements you are looking for. 

Regarding your question on how the USB 6008 will work, you do not need further hardware than the sensor, the USB 6008 and your computer.