Data Loggers

Check out HOBO from Onset Computer Corp.

Thanks

I will have a look at it HOBO. Is there any thermocouple data loggers you could think of for which I could write my own software to interact with my machine. In the sense like not a custom built software which reads in the values and stuff but something I can develop to suit my needs.

Cheers

Try Pace Scientific Inc. Charlotte, NC

If you prefer to buy british I can recommend:

http://www.picotech.com

Omni Instruments (Dundee) sell the Pace loggers in the UK but I think the price is nearer £400; still the cheapest we have found though!

Thanks HydroScot

I will have a look at it. I stay in Scotland as well. So doing business with Omni makes sense. I will look through their products and see how well it fits my research.

Cheers

I would stay with the TC-08! I have over 70 t/c's connected to monitor ovens & freezers. we write our own software for it in VB. They have been running for years and at distances of over 200 ft. using solid copper wire and adding an off set. We calibrate every 6 months.

google OMEGA

http://www.microdaq.com/

http://www.omega.com/

hello guest, depending on how many nodes your using you could go with a "one wire"

system. Primarily used in weather stations setups but growing in to other areas.

Here a link to 1-wire sensors & actuators

the thermal couple module is about half way down the page.

there also software or you can roll your own, also there are interfaces modules for computers and to do data logging, you will just need to google "1-wire" or "one wire"

to get started.

good luck

metalSmith's

Try this: http://www.phidgets.com/

Hi All,

I have been looking at the websites and products you have all suggested. I am not quite understanding the exact meaning of 'resolution'. Could anyone kindly explain me please.

In some products spec I see it as 1.0 C and in others its like 20 bits What does it mean?

Thanks

Hi All,

I am in need of your help. I am using a single 'k' type thermocouple with a TC - 08 data logger and this fulfills my intended purpose of monitoring a part of an electronic chip in 10 to 12 minutes.

If I need to reduce this time to say 4 to 6 mins what should you target. Can this be done by placing multiple thermocouples or by using data aqusition units instead of data loggers?? Can thermocouples be used for data acquisition as well?

Looking forward for your responses.

I sure hope someone with more current experience/expertise than mine will respond to this!

The Specs of the TC-08 indicate

Temperature accuracy Sum of ±0.2 % of reading and ±0.5 °C
Voltage accuracy Sum of ±0.2 % of reading and ±10 µV
Overload protection ±30 V
Maximum common mode voltage ±7.5 V
Input impedance 2 MΩ
Input range (voltage) ±70 mV
Resolution 20 bits
Noise free resolution 16.25 bits

Since you are measuring the temperature of a chip (and presumably a hot one, or you would not bother to measure it), lets assume your maximum temperature is of the order of 100°C. 0.2% of 100° is 0.2°, so the spec accuracy of the unit is ±0.2° ±0.5°, or ±0.7°C.

I suspect that the 20 bit resolution can be a bit misleading. With different types of TC, it can measure from -270 to 1820°C, a difference of 2090°. Unfortunately, that value is just over 2048 (the closest even power of 2), so it would be logical that the output of the device, in order to be able to indicate all possible values within its range, would use 4096 (the next even power of 2) whole divisions. This would indicate a temperature resolution of 4096/2²⁰, or 0.004°. The resolution is thus considerably better than the accuracy of the device, IF the software shows the full resolution output.

According to other specs, the TC-08 can take 10 readings per second. I'm not quite sure how to interpret what you mean by 'in 10 to 12 minutes.' I suspect you mean 'for a duration of 10 to 12 minutes.' Thus in 10 minutes you could take up to 6000 readings. There might be a problem with memory, especially if the software tries to store this data to the HD on the fly. Shortening the time will simply reduce the memory required, which might help if memory is currently a problem. On the other hand, their system requirements only indicate a minimum of 32MB of RAM. Surely you are using a computer with way more than that, so I doubt if memory is a problem.

This is using a thermocouple for data acquisition!

I have not seen the Pico software, but they do say you can control the data sampling rate, and that you can connect up to 20 devices simultaneously. Since you are using a single unit, I'm beginning to suspect that any limitations you currently have are due to software settings. Try looking at preferences and/or explore the menus for settings you can change.

Dick