mattw
New Member
Posts: 8
|
Post by mattw on Dec 26, 2018 19:51:25 GMT -5
I have a Lake Shore 366. In the Curve Handler software, I want to create a curve, and I have an Excel spreadsheet that I'd like to upload or copy and paste to create it. Can I upload or copy and paste the whole thing, or do I need to enter the data points one at a time?
Also, when I create a custom curve and write it to the 366, then go into Input Setup -> Curve to select the curve I created, it isn't listed as an option. If I go to Curve Entry -> View, I can see that the curve is there on the instrument, but when I go to select it in Input Setup -> Curve, it isn't there. My resistor is an NTC resistor, and I did change to NTC RCD (Cernox) in the Input Setup -> Sensor type, though it is not actually a Cernox thermometer. What should I do?
|
|
|
|
Post by Lake Shore Ogi on Jan 2, 2019 10:14:33 GMT -5
Dear Matt,
There are a few reasons that could be giving you trouble. First of all, I don't think you can paste everything from excel into the curve handler - unfortunately. You then have to make sure that your curve is in the right format. If I had to guess, your data might be in resistance vs. temp. If that is the case, it will not work. For our NTC RTD's, our instruments look for Log[base10](Ohms) instead of just Ohms in the curve. Below is the header and the first few points of how your curve should look. If you're still having issues, you can also send me your curve to service@lakeshore.com and I can take a look as well.
Sensor Model: CX-1010-AA-0.1L
Serial Number: X#####
Data Format: 4 (Log Ohms/Kelvin)
SetPoint Limit: 325.0 (Kelvin)
Temperature coefficient: 1 (Negative)
Number of Breakpoints: 192
No. Units Temperature (K)
1 1.47506 325.000
2 1.47957 319.000
3 1.48380 313.500
Best Regards,
Ogi K.
|
|
|
|
Post by Lake Shore Ryan on Jan 3, 2019 17:00:03 GMT -5
There is a way to load an Excel file onto a temperature controller like you have, but the process at the moment to do this is more complicated than I like. Here are the steps:
1. Run the Embedded Curve Handler software that can be accessed using the web server on the Model 336. Information on how to access this software if you don't already use the 336 web server can be found in Section 6.4.4 of the 336 manual. You can read about this software in Section 6.5.1. Note that this piece of software is different to the Curve Handler than you're probably using now (downloaded from our website?). This version runs on the 336 itself, so you would need to network with the unit via Ethernet.
2. Read from Instrument one of the standard curves from the instrument. Since you're working with a Cernox, I'd recommend reading the RX-102A standard curve since it is also an NTC sensor.
3. Write to file the curve and select .xls as the file format to save as.
4. From here you can open the .xls file in Excel and copy in your calibrated data. Keep in mind that the sensor resistance data is stored in log10(R) like Ogi said, so you may need to convert your data first in Excel. Also, it's important that the field showing number of data points matches the number of rows of data. You will also want to change the Curve Name and Serial Number data for the device. Also, I think the order of the points is important, so make sure your temperature values are in descending order as shown below.
5. Once you've made your modifications, open the modified .xls file using Read from File in Embedded Curve Handler and now you should see your custom curve.
6. Now you can Write to file and select .340 as the file format. Alternatively, you can skip this step and just write the curve directly to the instrument.
I've used this method before to modify existing curves for various reasons, but never to create new ones, so I just want you to be aware that you may run into some problems with accuracy. When we generate sensor calibration curves, our algorithm selects temperature steps and resistance values with the main objective of minimizing error and this is far from a simple process.
So I wish you the best of luck. Let us know what you ended up doing. Thanks!
|
|
mattw
New Member
Posts: 8
|
Post by mattw on Jan 7, 2019 17:55:07 GMT -5
Thank you. I have the data in an excel spreadsheet with temperature in one column and the log10 of the resistance in the other column. Where is the Embedded Curve Handler? I have the regular Curve Handler software and I don't see a "Read from File" option on it.
|
|
mattw
New Member
Posts: 8
|
Post by mattw on Jan 7, 2019 18:47:29 GMT -5
Hold on, I should have read your entire post, Ryan  |
|
mattw
New Member
Posts: 8
|
Post by mattw on Jan 7, 2019 20:45:32 GMT -5
Also, would it be possible in the regular Curve Handler to input a curve that is a function rather than two sets of data points? If I use my temperature/resistance data to create a function in other software of T = f(R), can I just input that function into the Curve Handler and write that to the Lake Shore 336? That would circumvent the problem of having to upload an Excel file.
|
|
|
|
Post by Lake Shore Ryan on Jan 8, 2019 9:32:39 GMT -5
Hi Matt, that sounds like it would be a handy feature to have for your application, but unfortunately we don't have that functionality built into the software. If you think this is something you're going to do a lot, you may want to consider creating your own script that uses the CRVHDR and CRVPT commands that can be found starting on page 130 of the Model 336 manual. I'm sure this would take a while to get working reliably, so this would only be something you'd want to try if you'll be creating a lot of curves.
|
|
mattw
New Member
Posts: 8
|
Post by mattw on Jan 10, 2019 17:57:17 GMT -5
OK, so I created a log10 data set for my resistance values, and I entered those values with the corresponding temperatures to the 366 using the Curve handler, then I selected that curve for the input. In Input Setup -> Input C -> Curve, it shows that curve I have created is selected, and in Input Setup -> Input C -> Preferred Units I have selected "Kelvin", but the display of Sensor C still reads out in ohms rather than using my curve to read out a temperature. What do I still need to change?
|
|
mattw
New Member
Posts: 8
|
Post by mattw on Jan 10, 2019 19:14:02 GMT -5
Never mind, I figured it out.
|
|
