Tulsa Calibrations : Best Consultation
Donate go go go go. Hey this is Nate we’re here with Travis. And here we are again podcasting on this great Friday afternoon talking about Tulsa calibrations and precision calibrations in Tulsa Oklahoma. So here we are discussing more calibrations discussing.
I’m not sure what are we going to discuss today. We’ve got a lot to talk about. I know that.
All right Travis So what are you thinking. What do you put on your mind today. I’m thinking it’s very humid outside. I’m thinking we’ve got a lot of rain. I need a calibrated chainsaw from Tulsa calibrations to cut up the tree that the tornado just about blew over your house and. Well I was fortunate enough not to have the tornado at my house but it wasn’t far away but it definitely left a mark. It left a mark. You know those crazy crossed ones that get you yes crazy ones they get you. This is going to be tough.
I have a feeling about this stuff yeah.
Tulsa Calibrations This podcast can be a little bit tougher today I just have got to get the that’s we see what do we do this week. See we calibrated some of micrometers and calipers and some dial indicators. It’s a pressure calibrations and torque calibrations calibrating our way to happiness each and every day. 1 1 1 Calibra at a time one calibration at a time. So the week has pretty much flown by pretty fast. I wonder how many calibrations we’ve done this week all together. I wonder what the count would be. I wonder what it could be hundreds.
I don’t know.
Maybe not. Anyway let’s see we did a survey today did some of the some thermal surveying for one of our customers temperature uniformity surveys of temper furnaces for a heat treat company.
Why don’t you walk us through the the the long drawn out steps of how you would adjust a badly poorly tuned furnace.
Tulsa Calibrations Well OK so I guess you’re referring to the furnaces and how they’re controlled by the temperature controllers. So those are what usually Honeywell temperature controllers and the temperature controller. Well it does just that it takes the thermal couple temperature input and determines what the temperature is and by operator operator interface you set a set point in there what you want the furnace to be. The controller then takes that information and makes adjustments to the output to adjust the gas to to cause the furnace to get to temperature to the setpoint temperature. But if the controller is having a hard time and doesn’t know how much gas to give it if you’re only five degrees away and it doesn’t give it enough gas to get there then something’s got to be done or or conversely to that if if you’re wanting to go to 500 degrees temperature and the current temperature is say 100 degrees and this thing decides it wants to put 100 percent output out. Then you may end up at a thousand degrees or something. So you’ve got to be able to go into the controller and make adjustments to it. And these are tuning adjustments.
And so we have to go in we change the tuning parameters which is also known as the ID which stands for proportion band integral and derivative. And by these three numbers the controller would know how to control the output to get the temperature to the set point and then control it at that set point for as long as you want it to control at this point. So anyway so in order to make some of these adjustments there’s several different kind of procedures that a person could use.
One of the ones that we have found that works really well is from actually from Omega. They
had come out with a paper. A white paper that discussed the the tuning of an ID controller. Is this all stuff that you see and tells the calibrations community. Tulsa calibrations is what does tuning of the controllers.
So anyway so we get this tuning tuning of the controller the tuning of the controller involves certainly like I said the proportional the integral and derivative values to get the best possible control.
For your furnace or for a particular process. And so also some of the controllers contain a Auto-Tune algorithm that can be used and auto Auto-Tune algorithm sometimes does not provide adequate control for the particular. Process. And so a person has to go in and do it. Manually. So if I was to walk you through some of this that we think we’d have to define a couple terms. And one of those terms is cycle time and the cycle time is basically is known as a duty cycle and it’s the length of the time from the controller to complete one on off cycle. So for example then if we have a 20 second cycle time and an on time of 10 seconds and an on off time of 10 seconds represents a 50 percent power output. That’s good to know. The proportion man is a temperature band that’s expressed in a percentage of the full scale with within which the controller proportioning takes place and the wider the proportion man is the greater the the area around the set point in which the proportion action takes place and sometimes this is referred to as gain which is the reciprocal of the proportion man. Isn’t this fun stuff. Man it’s very it’s very interesting. I mean we can just go on and on for days we should stuff we should we should.
I mean because it’s important to know the different equipment and the different needs and everything that’s here in the Tulsa calibrations community that is true.
So the next portion of this is the eye of ID and it is called the integral and it’s also known as a reset and the function of that if adjusted its a function which adjusts the proportion bandwidth with respect to the set point. OK. To up to compensate for the offset. So basically if the proportion band is set to a certain value and you have a certain output and you have an output does not get you to set point adequately then that’s where the integral or the reset comes in. So the reset can be adjusted to help to to basically bump the output up and continue to bump it up until it gets to setpoint. And then you have the derivative and it’s also known as the rate. And this sensor is basically the rate of the rise or the fall of the temperature. So if the temperature is on its way up towards setpoint it looks at the rate at which it’s going. And with that information it is just that a proportion band to minimize overshoot or undershoot. So those are the three parts of the controller is capable or I’m sorry the APD controller is capable of great control and stability when it’s properly tuned.
And so what some of the repercussions are you know what what what what what some of the ways you know the furnace isn’t properly tuned with one of the things whenever you’re walking around in the Tulsa calibrations community in the Tulsa calibrations area that you notice you know amongst these furnaces and ovens and you can look at it and know that you know it’s just not quite right.
You see the fat guys not happy because the cookies are burnt. So
when you walk in the office and people aren’t happy because their cookies are burnt then you know that there could be a problem with the tuning and the tuning parameters of the controller of the furnace calibrations furnace survey temperature uniformly survey makes less sense.
Can I just throw all those words in there you know a lot of sense yeah. So yeah I was talking more kind of like visually on the chart.
OK so you know what I was thinking about when I wrote you know because because we’ve been in the Tulsa calibrations community all day doing thermal surveys here in the Tulsa calibrations community we came out of Claremore to do a Tulsa calibrations and you know we were walking around and we could we could visually tell that well.
Some of them just weren’t as optimal. They weren’t quite optimized I think is the right word to use.
I think that is correct optimized. Well I’ll tell you what I mean I’ve had a really good time talking about tuning parameters of controllers and furnace. I think I think we could probably have another podcast to continue this great topic. Oh I hope so. I know I can’t wait. I hope we don’t have to wait too long to get started with that.
Oh I pray not. I would give up a steak to talk more about P.O.D. controllers.
So all right. Well that’s Travis been a good time.
And we’re going to talk more about P.O.D. controllers calibrations