usb 6008

[heang]

hello
As USB 6008 is able to measure +/-1V of analog input, i doubt if temperature sensor of 4.65mV/ celcius can be used to analyzed by using USB6008. It must be noise from temperature sensor. However, if resolution of USB 6008 is 12bit, it means that the discretization level is 2/2^12 which equals to 0.5mV. what my question is the suitability of using usb 6008 in my application? if the signal is to be filtered by software(by using labVIEW filter.vi)  instead of hardware, will i able to get accurate reading without any signal amplifier needed?

regards

[smercurio_fc]

That all depends on what level of accuracy you want. You may want to take a look at these articles:
http://zone.ni.com/devzone/cda/tut/p/id/4517
http://zone.ni.com/devzone/cda/tut/p/id/4018

[michenglaoxu]

You better need a signal conditioning device to linearize and amplify you temperature signal.  

[Christian Mergl]

Hey,

smercurios links will give you a good answer but anyway I would suggest to use a signal conditioning close to your sensor regarding this low voltages and the usage of the USB-6008.

Christian

[smercurio_fc]

Let's not forget that the 4.65mV/degC is the change in voltage, not the actual voltage that would be measured. Whether or not an amplifier is needed is all dependent on:

1. the temperature range of the sensor,
   
2. the output voltage range of the sensor,
   
3. the temperature range being measured,
4. the desired temperature change accuracy (i.e., do you need to see a 1 degree change, or a 0.5 degree change, or what?)
   

For instance, a thermistor with a temperature range of 0 to 100 degC and an output voltage range of 0-5 V means that you'd be measuring about 1.35V at room temperature. If you're trying to see if something is getting too hot, you'd probably be measuring something around 50 or 60 degC, which would mean you'd have a higher output voltage for the sensor.

[o枫o]

您好：我是刚刚开始研究LabVIEW的一名学生。前一阵子在网上弄到了一个题为：“基于LabVIEW步进电机PID控制系统的设计”。但那上面的程序图是在是太模糊了。昨天在这里看见你以前研究过步进电机。不知道您那里还有它的vi程序吗？如果有的话麻烦您发到我的邮箱：blfjvkwfn@126.com      万分感谢！！！！！

[RavensFan]

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o枫o wrote:

您好：我是刚刚开始研究LabVIEW的一名学生。前一阵子在网上弄到了一个题为：“基于LabVIEW步进电机PID控制系统的设计”。但那上面的程序图是在是太模糊了。昨天在这里看见你以前研究过步进电机。不知道您那里还有它的vi程序吗？如果有的话麻烦您发到我的邮箱：blfjvkwfn@126.com      万分感谢！！！！！

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You may want to post in a foreign language board such as  http://forums.ni.com/ni/board?board.id=5170 where there are people who may be able to read whatever it is you wrote.

[o枫o]

Thank you very much.But my english is very bad,I'm afriad they could'n understand what I said.

[RavensFan]

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o枫o wrote:

Thank you very much.But my english is very bad,I'm afriad they could'n understand what I said.

---

Maybe so.  But in an English forum as this one is, there will only be perhaps 1 in a 1000 people who will be able to read an Oriental language.  For the other 999 people, your post is just noise.

In one of the foreign language boards, (I don't know if those characters are Japanese, Chinese, Korean, or something else.) Everyone who browses those boards would be able to read it.

Message Edited by Ravens Fan on 04-09-2008 10:10 AM

[michenglaoxu]

Send me you resume. I may have more information for you.