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Temperature Transmitters

Discussion in 'Buy, Sell and Trade' started by Reloadron, Oct 19, 2010.

  1. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    OK, I am located in Cleveland, Ohio USA so I will limit shipping to the US just to keep it simple.

    What I have here are several Temperature Transmitters and am attaching a few images. More information on them can be found here. They are TT221 series so if you click the link and scroll down to 221 series you can click the manual link on the left for much more information. These are for type J thermocouple input and the full part number is TT221J1HM which is a 35 to 700 Degree F or 1.7 to 371.1 Deg C temperature.

    What that means is with a power supply (12 Volt min.) they output 4 - 20 mA for the given range. Max supply is 45 VDC and I generally use them in the 24 VDC power supply range. Place a resistor in series @ 250Ω 1% and you can have a 1 to 5 volt output to input to a uC, place a 500Ω resistor in there and you have 2 - 10 volt for a output. Attached is a circuit example.

    So what is my price? Free for a few with a simple stipulation or two. Please don't ask me for a few just to have. I would like to see a few forum members use them and post their projects and how they used them. I sent a few to a forum member several months ago and they were used to control a alloy bath temperature to make shotgun shell shot. They even mailed me photographs of the setup which was cool.

    The newer versions are fully programmable and thus at work we are replacing this type. I never throw anything away! :)

    I have 8 and will send the first 4 people who post in the thread they want a few (two) each. Postage is on me but remember I do ask they get used. They do not include type J thermocouples or power supply. Just the temperature transmitters. Therefore if you are unfamiliar with temperature transmitters like this please allow another member a chance to get a few.

    <Edit> They are a Type J TC Input I think my circuit shows Type K! </Edit>

    Ron
     

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    Last edited: Oct 19, 2010
  2. jrz126

    jrz126 Active Member

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    Hi Ron.

    Do you still have these transmitters? I would've expected them to be scooped up real quick.

    I'm interested in a couple. I'm installing radiant heat in my garage floor and I'm looking to build a datalogger to control it and measure the performance.

    I'd like to measure 6 temperatures. 2 to measure the slab temp, 1 to measure inside ambient, 1 to measure outside ambient. and 2 to measure the boiler in/out temps.

    I'd be looking for a few more if they were able to measure below freezing. But I could use them to measure the in/out temp of the boiler.

    Lemme know if you still have them and I'll PM you my address. Which side of Cleveland are you on? I'm practically right down the street.
     

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  3. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Absolutely I will send you a few. They would be great for the boiler in and out. Also, I never posted it but there were a few that were I think 32 F to 212 F. I am just not 100% on those. Where I work they were transitioning from Type J to Type K and now we use newer fully programmable units. Anyway, two are yours for sure.

    Actually we are in the SE burbs of Cleveland, in Bedford Heights.

    Next, I have a suggestion for you as to data logging if you aren't set up yet. Reasonable cost too. Take a look at the DI-148 Starter Kit which gives you 8 channels. The kit includes the software though I have written some stuff in VB for them. OK, so you are limited to a +/- 10 volt input and a slow sample rate but matters not as you are measuring temperatures so how many samples / sec do you need? Also, you power the temp transmitters I send wit a 24 VDC supply and place a 500 ohm 1% resistor in series with the 4 to 20 mA loop and you have your 2 to 10 volts = 35 to 700 Deg. F.

    This link is an example of something I did. Yeah, it's a mess but the pictures are from doing a computer case temperature experiment a few years ago. The software shown is something I wrote but the Dataq software includes some real nice and simple (scalable) software for data logging.

    Just PM me a mailing address and the postage is on me. :)

    Ron
     
  4. dave

    Dave New Member

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  5. jrz126

    jrz126 Active Member

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    Hi Ron,

    That DI-148 looks great. Pretty inexpensive too. That'd work pretty nice for a home electricity datalogger too.

    Not sure of the exact range, but I think I need to measure down to atleast -20F for the outside ambient. The inside (garage) ambient probably doesnt get below +20F thanks to my 1970's insulation. Not sure what the slab sensors need to be. +20F would probably be sufficent. I'm going to run antifreeze in the lines so freezing wont be an issue.

    You have any experience with temp. controllers? I could control it all from my PC, but then I'd have to leave it on 24/7, which I pretty much do already, but I dont want my garage to ice over if it crashes. I've used a couple at work that were programmable for the turn on/off temps and I think you could even tweak the constants for PI regulator.

    I sent a PM with my address. I really appreciate you just giving these away. What kind of stuff do you tinker with? I've got a basement full of stuff, maybe I can return the favor.

    Thanks,
    Jeff
     
  6. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Hi Ya Jeff

    I got your PM and give me a few days. Things are a little hectic this week.

    OK, before I forget, yes, I have plenty of controller experience. Controlling temperature is one of those things that really depends on how much you want to get into it. A residential wall type thermostat is a controller or things can get elaborate.

    Simple controller for example based on a temperature transmitter would be similar to what I mentioned earlier. The transmitter puts out 4 to 20 mA based on its range. So for example in the case of a transmitter with a range of 35 to 700 degrees F. Now if we run that 4 - 20 mA through a 500Ω resistor we get to 700 - 35 = 665 degrees span and 10 volts - 2 volts = 8 volts. Therefore 8 / 665 = 12.030 mV per degree F.

    Now the data logger little starter kit I mentioned is an 8 channel 10 bit device. A 10 bit A/D will give us 1024 quantization levels for the input which is in this case 10 volts. Now we have 10 / 1024 = 9.76 mV resolution. This isn't great but not bad for the application at hand. Consider a cheap A/D with all the software for $50 not bad at all. :)

    So for a simple home brew controller what could be done is use a comparator chip like the LM339 or since we only need a single comparator an LM393 or LM311. Run the voltage from the resistor into it (2 to 10 volts) and set a reference for the temperature set point. Drive a slave relay or a MOSFET to control whatever. Use compensation with the comparator circuit. Anyway, that would be a simple home brew controller.

    If you have any programming skills the DI-148 does have a few DO (Digital Out) lines that could be used but running all software based gets into things a little deep. Back to if computer crashes as you mentioned. :)

    Tell me more about what you want to control and the requirements and maybe I can help more. I'll also see what I can do on the ranges you mentioned.

    Ron
     
  7. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Packed today and will be sending in the morning. Sent a PM. Enjoy!

    Ron
     
  8. jrz126

    jrz126 Active Member

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    Thanks A bunch Ron, I'll definitely let you know once I get them.

    My plan is to keep the temp low most of the time, just enough to melt the snow off the vehicles. I want to be able to raise the temp when I know I will be working out there in the near future. I'll need to figure out what the time constant is so I can turn it on far enough in advance.
    Also need to figure out the best way to regulate it. Using the slab, ambient or some combination of both.
     
  9. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    My Pleasure!

    I think once you get control then you can tweak and peak Just let me know if you need help or anything.

    Ron
     
  10. jrz126

    jrz126 Active Member

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    Hi Ron,

    Got the package a few days ago. What thermocouple type is used with the white transmitters? The part number field on the label was blank.
    I ordered the DAQ yesterday and it should be delivered today. Even though the website said it was out of stock until the 8th.
    Hopefully I will have time this weekend to play around with it.

    You have any interest in hi-power switching devices? like 8000A peak SCRs?
     
  11. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Hi Jeff

    OK all the transmitters I sent were for Type J. The black ones are non programmable and set up for type J 35 to 700 degrees F. The white smaller units are programmable (you will see four little pins that are used for programming) and I programmed them for -30 to 170 degrees F. That gives you a 200 degree span = 4 to 20 mA on them. Like I said, get some good precision 500 Ohm 1/2 watt resistors and that will give you 2 to 10 volts scaling. The temperature transmitters already have CJC (Cold Junction Compensation) built in. Oh yeah, the older black units also have an LED that tells you a thermocouple is connected. I tossed in a few crimp tip thermocouples I made to get you going. Just remember the Red lead is NEGATIVE so think backwards. :)

    I am working Sunday but will try and make you a few drawings of a good basic setup. Lately work is busy so they are beating me up, head cold and all. :)

    When you get the little data logger you will need to connect it to a PC using a USB cable. Windows will see the new device. Then place the included disk in but don't run setup yet. Just let windows find the drivers and install them. It should discover the device twice and install two sets of drivers. Once that is done then install the software running setup from the disk. The software includes data logging software to record. Let me know if you have any problems. Hell let me know if you need anything. No problem at all and I don't need anything. Hell I just removed a few 3 phase 100 and 150 amp scr controller banks at work they will likely scrap. :)

    Ron
     
  12. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Attached is an image showing how to connect the Inor temp transmitters. That should get you started. Again, any questions or confusion, just ask.

    Ron
     

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  13. jrz126

    jrz126 Active Member

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    Hi Ron,

    Been super busy working in the garage, adding insulation and electrical. (Why you would only install a single outlet in a garage??). I got it figured out though. That DAQ is pretty sweet. I didn't realize you had to pay an extra $150 for the high speed version.

    Reason I was asking about TC types is that one of the black modules says Type K.

    Was it pretty difficult to interface it with VB? I'd like to get it into Labview. Be a piece of cake to implement a PI regulator in there. I could solve the PC crashing issue by having another circuit wired up so it kicks on at a lower temp. So if the PC fails it wont shut down completely.

    Also found these on Ebay: 4 Digital Red LED Volt DC 10V Panel Meter rescalable - eBay (item 370326104110 end time Nov-22-10 04:56:03 PST) I could have a digital readout in the basement.
     

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  14. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Uh, maybe Ron screwed up? I should have checked them close. There could have been a K in there. If you send it to me we offer a free return policy on free stuff. Just send it and I'll send another J type module. I'll PM an address. My bad. :)

    The reason I never mentioned the high speed version is I figured for temperature measurement the 240 samples/sec was adequate even with 6 channels that is a max of 40 samples/sec per channel. That keeps it around $50.

    As to VB I use VB6, I have the newer VB.NET versions but I just plod along in VB6 with the Dataq modules I use. I am not a programmer and I have no problem writing code for them in VB. They do offer extensive code samples in Lab View also.

    I have been working on a small little program that I'll link to in a few days. You can read all six transmitters connected to the the DI-148. It will read voltage, temperature and I am trying to program the DIO as a digital out so each channel has a set point. I can always get one digital out to work but when I add channels things go south on me. Worst case I'll have a single digital out. :)

    The meters look to be a good deal and they spell out rescalable. I haven't seen any that cheap before but the seller has a good rating. They should work.

    More Later
    Ron
     
    Last edited: Nov 11, 2010
  15. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    OK, here is a link to a little program to read 6 channels of a DI-148 and output on the D0 when analog channel 1 is below a set point. An image of the program is attached.

    Just click here to download the file as a zip. I suggest save it to your desktop then right click the zip folder and choose Extract All. That will create a new folder on the desktop. Open the folder and double click the .exe file to install the program.

    The program displays six channels in temperature and volts. The first 4 channels are for the white transmitters and the remaining two the black.

    This program only works with a DATAQ DI-148 starter kit. It was kept simple so make sure the DI-148 is connected via USB or it will just sit there looking back at you. :)

    Ron
     

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  16. jrz126

    jrz126 Active Member

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    Hi Ron,

    Thanks for the demo, I'm going to try to take a look at it tonight.
    Eventually, I'd like to be able to generate some plots of the data and upload them to my website real time.

    I have plenty of type K TCs around. So the type K transmitter is no problem.
     
  17. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    Mess with the demo and let me know what you think. If you need any help let me know.

    Ron
     
  18. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    Hey, jrz126! Sorry to butt in, especially a month after you posted this, but do you still have those SCRs? I am in need of a bunch and I haven't been able to find any. How many do you have and how much do you want for them?
    Again, sorry for jumping in like this :eek:
    Der Strom
     
  19. jrz126

    jrz126 Active Member

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    Well, since Ron isn't interested, I suppose I could extend the same generosity.
    How many did you need? and what are your plans for them? I have a bunch, most of them are the hockey puck style though. There are a couple of stud mount ones there, but I'm not sure of their specs.

    Those bricks there are 2500V, 1200A continuous IGBTs in case anyone was wondering.
     

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  20. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    In my research on various projects, I've seen several circuits that require high-power SCRs. One of the projects, for example, is a solid state tesla coil I found a while back that I wanted to try to replicate. I just thought it would be good to have, say, five of them on hand for projects such as this.
    Id like to thank you very much for considering my request. If there's anything I can ever do for you, just let me know :)
    Thanks!
    Der Strom
     
    Last edited: Dec 5, 2010

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