Measuring temperature using thermocouple and SCB-68 box

I used thermocouple and SCB-68 box to measure temperature. But the readings were fluctuating around the expected value. So I removed the thermocouple and short-circuited the differential input channels. As expected, the voltage reading was not zero and also fluctuating. It seems that there was something wrong with the SCB-68 box. What might lead to this and how to solve this problem? Thanks.

The problem could be either the SCB-68 or the DAQ card you are using to make the measurement. You should first ensure that the DIP switches (S1 - S5) of your SCB-68 are in the correct position for your application. Please refer to the SCB-68 User Manual for more information on this subject.
SCB-68 68-Pin Shielded Connector Block User Manual
http://digital.ni.com/manuals.nsf/websearch/74C86ADEF0E4813F86256C84007CB3AB?OpenDocument&node=1180_US
What do you mean by fluctuating? Full swings from 10V to 10V? Hitting one rail? Close to 0V but looks like noise in mV or uV? If your fluctuation is very slight, for example off by a few millivolts, than you could be picking up noise or your board could need to be calibrated. You can read more about accuracy and
calibration from the following web page:
Calibration Solutions from National Instruments
http://www.ni.com/support/calibrat/
If you have an E-Series Card you may be interested in running our Online E-Series Diagnostic Utility. This utility takes about 3 minutes to run, will perform a calibration, and will generate a report of anything that may be wrong with your board.
Online E Series Diagnostic Utility
http://www.ni.com/support/selftest/
Regards,
Justin Britten
Applications Engineer
National Instruments

Similar Messages

Temperature control system using thermocouples and cooling fans

Greetings labview community,
I'm fairly new to the labview program and though I have watched the tutorial videos and tried to search these forums I couldn't find a solution to my problem.
I need to write a program in labview that controls the temperature via use of fans inside a case with heatsinks and various electronic parts.
In particular I want to use two thermocouples, in order to measure the temperature of two transistors (one in each side of the case), where heatsinks are placed on top of them.
When the temperature is above 25 degrees, a fan should activate. The fans speed should be faster, the longer the temperature stays above 25 degrees, until it drops down to 25 degrees.
How can this be done? I thought of using a "mask and limit testing" for activating it, but I can't figure out how to control the speed of the fan in a loop automatically based on the temperature.
Here are some of my specifications:
USB-6009 (this was provided to me and is therefore my only option)
Labview 2011
NIDAQmx 9.5 driver
2 thermocouples (one for measuring the temperature for each transistor and activating one fan)
2 fans 0-5V
Below you'll see an attachment of the program I've wrote so far (just for one set of thermocouple-fan) and I'm using a slider to simulate the input from the thermocouple. If there is anymore information needed, tell me.
Thank you very much.
Attachments:
Temperature sensors and fan activation.vi ‏130 KB

Hi Lomedil
What you have is a general control problem. This statement:
"The fans speed should be faster, the longer the temperature stays above 25 degrees, until it drops down to 25 degrees. "
Is an indication that you at least need a PI-controller, or you could use a PID-controller. The I in PID stands for integral and that means that the longer you have the same value different from your reference the larger the control signal will be and thereby the faster the fan will spin.
I would recommend you to have a look at the following article to learn the basic principles of control theory:
PID Control
http://zone.ni.com/devzone/cda/tut/p/id/6440
To find the coefficients in your design you can either choose to make a mathematical approximation of your test setup and then calculate the three constants Kd, Ki, Kp using this model, or you can choose to estimate the parameters on a "trial-and-error" basis until you have the desired response time / overshoot i.e.
In general you should note that designing a control application on a General Purpose O/S as Windows will not give you deterministic timing, thus your control loop can be more unstable than expected, design your controller with this in mind! For the fan operation it should not be a problem but for more advanced control purposes your would always use a Real-Time system like the singleboardRIO, compactRIO or setting up a standard PC as a LabVIEW Real-Time Target (Converting a Desktop PC to a LabVIEW Real-Time Target - http://zone.ni.com/devzone/cda/tut/p/id/2733)
Best Regards
Anders Rohde
Applications Engineer
National Instruments Denmark

How to measure the rpm using NI 9411 and counters

How to calculate the rpm of a shaft using NI 9411 and counters?

http://forums.ni.com/t5/Signal-Conditioning/measuring-rpm-using-DAQ-device/m-p/2571131#M7353
Additionally, if you set it to read a degree instead of pulse, your calculation will change a bit, but I'll leave that to you.

Why can't I use a Vision+ and a YouView Box

Hi,
I'm with BT and pay £5 a month for BT Vision. I have their YouView box in one room. They only allow BT Sport on the YouView box if you have fibre and there's no fibre in my area. I asked BT if I could run a YouView box and BT Vision box at the same time and they said no. I ordered a BT Vision Card for a tenner via the online BT shop and bought a BT Vision+ box off eBay for 99p. My assumption was that I couldn't run both boxes at the same time (ie connected to the hub)......not a problem I can only watch one TV at a time!
I've disconnected the YouView from the BT Hub and connected the Vision+ Box but I get a C03 message saying my Vision+ isn't activated. Am I right in thinking BT must be able to activate one of two Vision services depending on the box? My initial assumption was that only one box could physically be connect at any one time.
Has anyone else experienced similar? Is there any way around this? Seems unfair as I am a BT Vision customer, I am paying £5 a month and if I want to watch BT Sport I have to give up my YouView box. BT say I can watch their channel via the web.....not being funny but a simple google search and I could watch their channel without even needing to sign up!!!!!
Thanks
Louis

It sounds like the 99p BT Vision+ box is running the Classic software rather than the New Look software. This is something you really should have checked before buying a second hand box. Once such boxes are deactivated they are effectively a door-stop unless BT choose to reactivate them. The box would need to be reactivated and then BT would need to send the New Look software upgrade to it in order for you to be able to use the viewing card for BT Sport.
I don't know, but suspect that BT would be reluctant to activate and upgrade a box that wasn't issued to you directly by them. They have been gradually turning off the Classic software over the last year or so and it involves older licensing agreements with Microsoft and content providers. Plus it might cause the central system problems now that you have a newer BT Youview box associated with your account. I suppose there's no harm in asking though?

Can NI myDAQ ai0 and ai1 be connected directly with thermocouples to measure temperature???

Hi,
I am trying to use myDAQ to realize both temperature measurement and digital output.
By reading this page I have learned that how I can create a task for temperature measurement using thermocouple with a certain NI device.
http://www.ni.com/white-paper/14338/en/
What I found to be really interesting is that when I create a task for myDAQ temperature measurement using a thermocouple when my NI myDAQ is connected with my PC, two AI ports ai0 and ai1 both appears in the create task window!!
I never found any information from NI myDAQ manual that "AI0 and AI1" can be connected directly with a thermocouple to measure temperature without using additional conditioning system. But this window suggests that myDAQ can be used in this way, is it?
I am still trying to do it this way, and I'll post some results here again.
I would be really appreciate if anyone could confirm or disprove my guess. Thank you.
PS:
Attached is the

Attached is the screenshots for "create new task" in NI MAX
Attachments:
1.JPG ‏60 KB
2.JPG ‏64 KB

Problems on measuring temperature using thermocouples connected to SCB-68 terminal block

I have problems on measuring temperature using thermocouples connected to SCB-68 terminal block.The thermocouples were connected to the differential channel 1 and a return path for the instrumentation amplifier bias currents and a 4 Hz low pass filter were both developed. But the readings were floating and jumped randomly between 0 and 200 Deg Cel abnormally.The CJC on the terminal block was disabled and a new one was developed by myself. However, the readings for the CJC were accurate and quite stable. So what is the reason for the floating of thermocouple readings? Did I miss anything that I need to do? Thanks.

Are your TCs floating or grounded? Basically, if your TCs are mounted to a metal test article and the object is grounded to earth, then, the TCs are grounded -- and very likely contaminated with ground loops. You will need to reference the TC inputs accordingly. These ground loops will cause the TC data readings to float - recall that TC readings are in the millivolt level. It does not take much of a ground loop to ruin a TC measurement.
Also, try this... first, set the filter to 10KHz and sample for a few seconds at 20 KHz (take 32768 data points). Now subtract the mean value from the trace and perform an FFT on the data. Look for the dominant frequency. Is it 60 Hz or some multiple? If yes, the likely cause is a ground reference problem.

How do I run a J-type thermocouple to the usb-6363 DAQ and program labview to measure temperature?

I have a usb-6363 DAQ and a J-type non-contact thermocouple that I am looking to connect and measure temperature through. However, the DAQ does not have any T/C inputs, which is needed to measure in the thermocouple temperature. I am connecting the thermouple to an analog input (+/-) and I am not looking to buy an amplifier, converter or any other hardware. I believe there is a way to program labview to read in the voltages of the thermocouple and convert it into accurate temperature readings. Any help/ideas?

Hello George,
This tutorial should step you through the basic process of configuring the device and connecting the thermocouple:
Tutorial: Connect Thermocouples to a Data Acquisition (DAQ) Device
http://www.ni.com/gettingstarted/setuphardware/dataacquisition/thermocouples.htm#Connecting a Thermocouple to Your Device
From there, there are a number of things you can do- I'd recommend taking a look at the LabVIEW shipping examples (Help>>Find Examples...) as well as the DAQmx getting started tutorials:
Getting Started with NI-DAQmx: Main Page
http://www.ni.com/white-paper/5434/en
At first glance, the 6363 you're using should have enough resolution to acquire usable data from a thermocouple- if you attempt reading raw voltages be sure that the acquisition range is configured for +/- 0.1V, though.
Regards,
Tom L.

Can I measure temperature using 6013 & 68LPR?

Hello, from hardware I've got Multifunction DAQ (6013) and Therminal Block (68LPR). From software I've got VI Logger (1.0.1) and NI-DAQ (6.9.3). Using this, can I measure temperature with K-Type therminals? (Everything is installed and ready to go)
If yes, how can I connect K-Type therminal to thermal block? Are there any instructions on how to use VI Logger to perform similar task to this one?
Also what I want is, the temperature that has been read (for an hour, every 5mins) to be written in a file. Is it possible to write to a file using VI Logger?
Thank you!
Regards Slav.

Hello:
I answered this questions over here:
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=50650000000800000041CA0000&UCATEGORY_0=_30_%24_12_&UCATEGORY_S=0&USEARCHCONTEXT_QUESTION_0=%2B6013+%2Btemperature&USEARCHCONTEXT_QUESTION_S=0
Sincerely,
Brooks B
Applications Engineer
National Instruments

How can i measure temperature using thermocouple using labview?

please list out the procedures to be followed to measure temperature using thermocouple using labview.

Do a search in the LabVIEW Example Finder (Help->Find Examples). There are a ton of simple Analog Input examples in there using DAQmx. One you might be most interested is "Thermocouple - Continuous Input.vi".
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

Max6675 for k-type thermocouple temperature reading using arduino and labview

Hi; I am trying to measure temperature using arduino mega +labview 2013 +k-type thermocouple+max6675.
I am using LIFA interface.
The circuit digram and labview file is attatched
I am stuck on spi read/write palet. How to read 12 bit max reading and convert it to temperature in degree celcious?
Max6675 produce output in 12 bit, and measure 0-1023 centegrade. According to this the
Temperature (C0)= max6675 output (12bit)* 0.25. how to set this formula in labview?
Pin connections are
Max6675 breakout board pins
Arduino Maega Pins
GND
GND
VCC
5 VOLTS
SO
50
CSK
52
CS
12
Attachments:
max6675.vi ‏38 KB
max6675 vi diagram.png ‏42 KB

Hi Saeed780,
We have a discussion board specifically for questions about using the LabVIEW Interface for Arduino. Can you please post your question to the Arduino board?
www.ni.com/arduino
Catherine B.
Applications Engineer
National Instruments

Measuring temperature and acceleration simultaneously

Hi,
I am having problems getting a correct and stable temperature measurement, I think the acceleration measurements are correct. I am using a daq PCI 61110 and the temp sensor is a type-k thermocouple I tried switching the thermocouple with a probe but the result did not change and I have checked the examples to see if I have gotten something wrong in my code but I can't seem to find it. Please could somebody help me and the vi is attached below.
Solved!
Go to Solution.
Attachments:
MultipleChannels_Created.vi ‏70 KB

I don't know your DAQ card, but I assume you are measuring in the voltage range for the accelerometer and them try to measure in the µV from the TC.
If you have channel crosstalk, your weak signal from the TC gets buried in noise.
Try to have some input channels connected to GND inbetween, maybe that helps.
Wait, I took a look into the spec (BTW 6111 or 6110??) your minimum resolution is 98µV, that would equal around 2K resolution, accuracy is 353µV (around 8K with type K TC ... not quite the right card for a thermocouple reading!!) Well and you don't have a CJ compensation....in other words: You don't have the right DAQ for thermocouple readings.
NI has a USB thermocouple device that woul fit your needs and is not too costly... or use a B5 module or other thermocouple signal conditioner with a 10V output.
Depending on your needs maybe a small NTC with a resistor as an voltage divider can be used to measure temperatur ...
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

Simple VI to measure Temperature using Agilent 34901A

I am trying to measure/record temperatures using Agilent 34901A and 34970A. I have all the T type TCs connected. I am not familiar with Agilent drivers so if anyone can provide some guidance. I just need simple VI. I am familiar with typical DAQ Assist VI and acquire signal from NI Hardware but no experience with Agilent. I got the drivers for Agilent but it seems much more complex than I need it to be.

I have been messing with a variation of Agilent drivers for the last couple of days. Labview's built in Visa drivers don't handle Agilent stuff quite correctly, and so you need to install their driver version (with the Agilent IO Libraries Suite). There is lots of documentation showing you how to configure LabVEW to work with their Visa drivers. Once you get that taken care of, I'm sure there are sample programs you can model off of. For example, try here:
http://www.home.agilent.com/agilent/editorial.jspx?cc=US&lc=eng&ckey=1838058&nid=-11143.0.00&id=1838...
And don't forget to apply the thermocouple coeffecients in to your program if you scan the voltages directly
http://srdata.nist.gov/its90/type_j/jcoefficients_inverse.html
Edit: Typo!

Report using Tabular Model and Measures based on Distinct Counts

Hello,
I am creating a report that should present something like this:
YEAR-1 | MONTH-1 | MONTH-2 | MONTH-3... | YEAR | MONTH-1 | MONTH-2 | MONTH-3...
My problem is that when designing the dataset to support this layout I drag the Year, Month and Distinct count Measure, but on the report when I want the value for the YEAR level I don't have it and I cannot sum the months value...
What is the best aproach to solve this? Do I really have to go to advanced mode and customize my MDX or DAX? Can't basic users do something like this that seems so trivial and needed?
Thank you
Luis Simões

Hi Luis,
According to your description, you create a Reporting Services report using Analysis Service Tabular Model as the datasource, now what you want is sum the months value on year level, right?
In your scenario, you can add the Month field to column group, add a parent group using Year Field and then add a Total on Month group. In this case, Reporting Services will sum the months value on Year level. I have tested it on my local environment, the
screenshot below is for you reference.
Reference:Lesson 6: Adding Grouping and Totals (Reporting Services)
If this is not what you want, please describe your dataset structure, so that we can make further analysis.
Regards,
Charlie Liao
TechNet Community Support

Using USB-8451, and AD7747 from Analog Devices to measure capacitance and convert the capacitance to digital output

Hello,
I am new to LabView and data aqusition. I have LabView 8.5.1 installed on my laptop, and I studied the Getting Started document of LabView, except the data aqusition chapter.
I have microfabricated a differential capacitive sensor, and now I want to test the capabilities of my sensor.
After asking NI engineers, I have been suggested to use USB-8451 with AD7747 (24-Bit Capacitance-to-Digital Converter) from Analog Devices because AD7747 has I2C serial interface.
I have ordered USB-8451, AD7747, and Evaluation Board for AD7747. And I am waiting for them.
Are there any suggestions about how to connect my differential capacitive sensor to AD7747, and eventually to USB-8451?
You may want to know some further information to answer my question:
*The sensor is similar to the sensor on pages 501, 514, and 515 of "Microsystem Design" book from author Stephen D. Senturia.
*The datasheet for AD7747 can be reached from this link: http://www.analog.com/static/imported-files/data_sheets/AD7747.pdf
*My purpose is to make a very precise and accurate "displacement measurement micodevice" by using "the change in the capacitance" during the motion of the mobile fingers of the sensor.
As an initial challenge for myself, I will feel satisfied if I can measure the capacitance change in my sensor when I apply an external mechanical disturbance to my sensor. For example, there must be a change in capacitance if I just swing my hand from top of the sensor region.
I am looking forward for your reply,
Thanks in advance,
Sincerely,
sriverfxtr

Hi Aaron,
Here you go, this is made with a USB-8452.
When you run the code tick the power en dac enable box on.
Maybe you can help me with my problem, I want to use a fiber to sense light from a led.
Do you use any fiber hardware with the TCS3414?
gr,
Attachments:
TCS3414.vi ‏63 KB

Need to Measure Light Freq. using photodiode and have it analysed by FFT, details below.

I a new to LV. Project is to measure light freq. using photodiode heald against a TV screen. Am required to have it analysed by FFT, I have read lots but still at dead end of which VI I can manipulate, tried Spectrum Analysers but not right. Need it to collect at rate of at least 100/sec. I am using a CB-68LPR I/O and PCI-MIO-16E-1. Photodiode is connected to an amplifier and filter before it is hooked into the connector board so signal is clean. I will be measuring freq. of ciliary beat where photodiode placed against a TV screen.

Julesy wrote:
> I a new to LV. Project is to measure light freq. using photodiode
> heald against a TV screen. Am required to have it analysed by FFT, I
> have read lots but still at dead end of which VI I can manipulate,
> tried Spectrum Analysers but not right. Need it to collect at rate of
> at least 100/sec. I am using a CB-68LPR I/O and PCI-MIO-16E-1.
> Photodiode is connected to an amplifier and filter before it is hooked
> into the connector board so signal is clean. I will be measuring
> freq. of ciliary beat where photodiode placed against a TV screen.
Hi Julesy,
are you shure what you want ti do?
TV screens don't show pictures, they show a point (3 points on a colour
TV) with changing intensity passing by very fast.
For instance, if you h
ave the PAL Standard, each picture is built with 625
lines, in 20 ms, interlaced. This means, 64 ?s line with the leading and
trailing overhead. The visible part of a line is aubout 52 ?s long.
If you attach your fototransistor to the screen, and its diameter may
cover a circular area of maybe 3 mm and the visual part of the line would
be 520 mm, then: And if this covers four of the screen lines, then you
will receive pulses of 0,3 ?s length if the line passes the center of the
fotodiode. Not passing the transistor in the center would give back an
even shorter pulse.
And if you get all this working (which I don't think) then you would
measure 2 groups of pulses every 10 ms with 2 pulses each (remember
interlacing).
Even if all the DAQ would work, is your fototransistor fast enough. Think
about miller capacities. Its not so simple at it seems first to solve this
measurement problem.
Please let me know what you intend to do. I was an TV- enginear many years
ago, and I don't remember ev
erything relevant anymore, but there are some
hardware- related things to be aware if if you want to measure TV-
signals.
Bye,
Rainer

Measuring temperatur​e using thermocoup​le and SCB-68 box

Similar Messages

Maybe you are looking for

Measuring temperature using thermocouple and SCB-68 box