Mettler-Toledo International Inc. (MTD) Earnings Call Transcript & Summary

Welcome to Mettler-Toledo's lab webinar. My name is Renee Doran, and I'm a lab market specialist here at Mettler-Toledo. Get the most out of today's webinar. Don't worry if you miss anything, we will have it on demand on our website shortly after this live session. Participate in polls. We would love to hear your perspective and also there will be a survey at the end of the webinar. Utilize the chat function. Enter your questions throughout the webinar. If you're having technical issues, go ahead and reload your browser first to establish a new connection. We offer a broad ranges of solutions across our customers' value chain. This will help you to streamline your processes, enhance productivity, reach compliance with regulatory requirements and optimize cost and reduce waste. And now on to the webinar.

Welcome to our seminar on calibration and adjustment for thermal analytical instruments. In today's seminar, I'll explain why regular calibration and adjustments are important during the lifetime of your instrument, I'll provide background information, describe the simple workflow for calibration and adjustment, show you the different adjustment possibilities, and lastly, I'll present a unique concept for Mettler-Toledo, FlexCal, the database for adjustment parameters. Let's talk about your motivation for calibration and adjustment. Generally speaking, each instrument comes fully adjusted from the manufacturer. So you might ask yourself, why should I calibrate and adjust my instrument then? With time, every high precision instrument suffers from wear and tear. This has an impact on its performance, and of course, on the reliability of the results. Therefore, it is highly advisable to schedule regular calibration routines as part of a basic maintenance plan to uncover any deficiencies. The goal of calibration and adjustment is to provide a measuring system that always delivers reproducible and accurate results. Before we move on to the actual calibration procedure, I want to clarify a few terms. One set of terms deals with statistics and the other set with calibration and adjustment. We need to be familiar with these terms first in order to understand what we are trying to achieve. What are trueness, accuracy and precision? These 3 terms deal with the distribution of results obtained during a set of measurements. Trueness is a parameter that describes the closeness of agreement between a mean value obtained from a large number of test results and an accepted reference value, also known as the true value. Accuracy is a parameter that describes the closeness of agreement between a test result and an accepted reference value. Precision is a parameter that describes the spread of data around a mean value. If we look at the figure on the slide, the measured value should lie as close as possible to the true value and the standard deviation, which describes the precision, should be as small as possible. The next slide illustrates this concept in the form of a bull's eye. Only in picture A do we get accurate results? The spread of data is small and the data points are close to the center of the bull's eye. This is what we want to achieve if we want trustworthy results. The pictures B, C and D represent undesirable results. We certainly have a mix of random and nonrandom hits, but the results are definitely not acceptable. In the next section, I'll explain how we can achieve the best results, as shown in picture A. In the previous section, we talked about reliable results from a statistical point of view. We want to be able to rely on the data that the measuring instrument has delivered. But how can we achieve this goal? We must invest a little bit of time and effort to calibrate and, perhaps, adjust the instrument as part of a regularly scheduled maintenance plan. But before we move on to that procedure, I want to define a few more terms: calibration, adjustment, tolerance limit and reference substance. Calibration is the act of checking, by comparison with the reference substance, the accuracy of a measuring instrument. This means that you are making a comparison of a measurement result using a reference substance for which the true value of the measured property is known. Adjustment is defined as modifying the specific instrument parameters so that the measurement result of the calibration performed afterward are within the tolerance limit. The tolerance limit is defined as the specified outer limits for permitted deviations from a true value. The tolerance limit is the responsibility of the operator and depends on his requirements regarding accuracy. Ideally, the measuring system should produce results with an error less than the tolerance limit defined by the operator. For the calibration measurements, you need calibration methods and you also need standards, notably known as reference substances. A reference substance is a substance that is suitable for the calibration measurement and whose specific properties used for the calibration, such as its melting point, enthalpy of fusion or modulus, are well established and accepted. A reference substance is deemed suitable if it is easy to handle, readily available and stable. Certified reference material is a reference substance, one or more, of whose property values are traceable to primary standards. All reference substances are delivered with a document certifying certain properties of the material. Mettler-Toledo, for example, offers metals such as indium, zinc and aluminum. These substances are certified for their purity, but not for physical quantities, such as enthalpy. A certified reference material comes with a certificate for the certification of the glass transition of a particular substance. For regulated areas, certified reference materials should be available and can be obtained from LGC, NIST or PTB. However, if you need to certify your instrument at high temperatures, you may encounter some restrictions because no supplier can deliver such certified materials. For example, no substances are certified for enthalpy at 1,000 degree Celsius or above. Depending on its type, each instrument has different parameters that need to be considered for calibration. The temperature needs to be calibrated for all instruments. In addition, the specific quantity measured by the instrument has to be calibrated. For example, heat flow for DSC, or displacement in TMA. Unfortunately, most of these quantities are affected by the experimental conditions. The techniques that require crucible, for example, are subject to the properties of the crucible, and these have an effect on the measurement result. Such properties are thermal conductivity, mass and size. Other such experimental factors are the furnace atmosphere, the purge gas flow rate and the various sample holders used in each type of experiment. Fortunately, these terminological effects can be eliminated by calibration, and the measured values for your sample will not be influenced by these external factors. Let's see how this is done. So when is calibration called for? Some possible instances are: with any new instrument, when a specified time period has elapsed; when an instrument has suffered a shock or experienced vibrations, which potentially may have put it out of calibration; whenever observations appear questionable. The calibration and adjustment of any instrument consists of two main steps: preparation and following a simple workflow. I'll describe these steps in detail as we go along. First, we're going to start with preparation. This consists of defining the measurement combination and method. This includes all of the parameters of your experiment, such as choosing the crucible, the atmosphere, the heating rate, et cetera. The methods for your calibration could either be supplied by the manufacturer or you can develop your own methods for your specific needs. You also need to define the tolerance limits for your analytical procedure. You should not forget to define the calibration interval, select the right number and type of reference substances. I will discuss reference substances in the next section because it's very important. Lastly, should your analytical procedure change, you may have to adapt your calibration method accordingly. Imagine that you have to calibrate your instrument over a broad temperature range. In this case, it is not sufficient to calibrate for just one temperature. You should choose several reference substances. The diagram shows a theoretical error curve and a parabolic correction curve based on 3 reference substances over a wide temperature range. The error range is minimized between 100 and 500 degrees Celsius between the 3 reference substances. At temperatures much lower than 50 degrees Celsius, the air curve diverges excessively. This can be seen on the upper left side of the picture with the blue curve. Note that for 2 reference substances, the error range is much larger. This can be seen from the red line on the lower left side of the picture. We can, therefore, draw the following conclusions: one, the more reference substances, the better; and two, the reference substances should cover the range of interest. You should not extrapolate 50 degrees C above or below the outer tolerance limits that you have defined. After you've completed the preparation and have performed the calibration, the decision-making phase begins. They're generally 2 routes. One, if the calibration values are okay, then you can measure your samples. This is, of course, assuming that the calibration interval hasn't expired. Or two, if the calibration values are not within the tolerance limits that you have defined, then you need to adjust the instrument. Assuming the results of the calibration procedure require that you adjust the instrument, then here, too, you can follow a simple adjustment procedure. I've based this on the following examples on the parameters for a DSC. These are Tau lag, temperature and sensor adjustment. Some of you may not encounter the term, Tau lag. Therefore, I want to briefly describe what it is without going into too much detail. It's a time constant describing the behavior of the furnace, and it guarantees that the apparent influence of the heating rate has no effect on the results. Note that each instrument is already adjusted at the factory for Tau lag. If really necessary, this can be readjusted by a specialist. Let's focus on the large picture on the right-hand side of this slide. This is an enlargement of the area marked blue on the left-hand side of the slide. The workflow for performing an adjustment is simple. For each calibration type, temperature and sensor calibration, respectively, the procedure is the same. Since the values do not lie within the defined tolerance limits, you have to adjust the instrument. To do this, you can, of course, use the calibration results. As a final check, run the calibration method again to verify that the adjustment was successful. If the adjustment was successful, you can continue with your sample measurements. If the adjustment was not successful, you need to adjust the instrument again. To summarize the procedure, one full loop consists of calibrating, adjusting, calibrating to check for correct adjustment, and measuring your sample. The ideal situation is when the results obtained after an adjustment procedure is no longer influenced by experimental factors, such as heating rate, crucible or gas flow rate. So far, we've covered a lot of theory about statistics, calibration and adjustment. For the next few minutes, I'd like to show you the difference between instruments that have been properly adjusted, and those that are not well adjusted as well as the effect this can have on your results. The first example illustrates how the onset melting temperature of indium is apparently influenced by the heating rate in picture A. It seems that by increasing the heating rate, the onset temperature shifts to a higher temperature, which is physically wrong. The falsely recorded onset temperatures are corrected by a Tau lag adjustment. As a result, we see corrected curves in picture B, and the onset melting temperatures now agree with the true value of 156.6 degrees Celsius. In the next 2 examples, I will talk about temperature adjustment for dynamic and isothermal measurements. First, let's discuss dynamic measurement. In picture A, we see that the onset melting temperatures and the peak temperatures for indium and tin are significantly shifted depending on the heating rate. The measured values for these substances differ greatly by several degrees in each case. After temperature adjustment, the values agreed perfectly for each substance. Not only do we have to consider temperature adjustment for dynamic measurement methods, this is also important for isothermal measurement methods. Isothermal methods are used for kinetic studies, OIT measurements and for absorption measurements. How can we make sure that the temperature reading is correct under isothermal conditions? For this purpose, we've used indium and tin as our reference substances. Each substance is used for one specific temperature, instead of a temperature range, as is the case with dynamic temperature measurements. For both substances, the melting onset temperature is incorrect in picture A. For indium, we have a difference of 0.3 degrees Celsius. And for tin, even 2 degrees Celsius. After adjustment, the melting temperature agree with true values. You can see the difference in picture B. We've arrived at the third example, sensor calibration and adjustment. All instruments have a sensor, but not all measure the same properties. The next few slides show the different calibration and adjustment possibilities for several instruments with respect to the sensor. In the case of the DSC, the most important sources of non-reproducibility are the heat transfer between the sensor and crucible and between the crucible and the sample. These influences are eliminated when the DSC is properly adjusted using certified reference substances. Thermogravimetric analysis is a technique that measures the change in weight of a sample as it is heated, cooled or held at a constant temperature. The heart of the TGA is the ultrasensitive Mettler-Toledo balance cell. Correct weight adjustment is of vital importance for this instrument. You have the option of performing an internal calibration with two [indiscernible] or an external calibration with certified weights. Thermomechanical analysis is used to measure the dimensional changes of the sample as a function of temperature. One of the most frequently studied properties is the expansion coefficient. Samples can shrink or increase in length when heated. For the TMA, the ability to correctly measure displacement is, therefore, a key parameter that requires regular attention. You can adjust the length using different certified gauge blocks. Dynamic mechanical analysis is used to measure the mechanical and viscoelastic properties of materials as a function of temperature, time and frequency when they are subjected to periodic stress. The desired modules can be calculated from the measured force and displacement amplitudes taking into account the specific geometry of the sample. Therefore, the instrument needs to be calibrated for length and force so that the correct modulus can be determined. This requires certified gauge blocks and a spring. An extremely precise spindle for the Z position, that is capable of defining on micron steps, allows for fully automatic length adjustment after the spindle has been adjusted with Gauge box. In addition, a certified spring is used to calibrate the piezoelectric sensors over the whole force range. The modulus accuracy can be proven by measuring a crystal silicon bar and a 3-point bending clamp according to the specified method. This procedure is, of course, only valid for silicon. The details of the measurement method and the expected value range can be read from the certificate included with the special reference sample. If the modulus falls within the specified range, you have verified the modulus accuracy. You can order this set from Mettler-Toledo. The instrument should be able to provide values that are independent of the heating or cooling rate, crucible type or gas atmosphere in the furnace. Each measuring cell used should, therefore, also have its individual set of calibration parameters and not be influenced by other instruments or by changing the controlling unit. To achieve this exceptional goal, Mettler-Toledo has implemented the FlexCal option in its STARe system, which includes the methods and the database to store and handle the necessary calibration parameters. Each instrument linked to the system has its own ID related to the actual calibration parameters. Each instrument specific set of parameters describes primarily the relationship between temperature, heating rate, crucible, gases and sensor type for the standard setup. With the database supported calibration model, FlexCal, thermo analytical results such as the onset of melting or heated fusion, no longer depend on the heating rate, the type of crucibles or the gas atmosphere selected. For ease of use, a new total calibration method performs a complete calibration, using 1 or more reference standard. The database supports the GLP consistent documentation of the actual calibration parameters. As we have seen, instruments that are not properly adjusted will give inaccurate and inconsistent results. Therefore, it's important to regularly perform a calibration and check it against the defined tolerance limits. This is essential for every laboratory to help ensure the integrity of your results. In addition, Mettler-Toledo has well-trained service and sales engineers who can assist you with equipment qualification, calibration and adjustment, training and application advice as well as provide assistance for service and maintenance issues. Finally, I would like to draw your attention to information about calibration and adjustment that you can download from the Internet. Mettler-Toledo publishes articles on thermal analysis and applications from different fields twice a year in our UserCom, the Mettler-Toledo biannual technical customer magazine. Previous issues can be downloaded as PDFs from our website. Additionally, you can download information about webinars, application handbooks or information of a more general nature from the website seen on this slide.

I hope you enjoyed the webinar. Please scan the above code for more lab webinars. Gain access to our wide knowledge base and tools by visiting mt.com. There, you can access white papers, guides and user newsletters. And now on to questions.

Hi, everybody. I'm happy to answer any questions, if there are any. I also just posted some useful links about from different thermal analysis topics into the chat. You may want to have a look at some of those. So if there might be a question coming into the chat. We've got some people typing. One of the most important things that I was always taught early on, never trust an instrument. So that's what this webinar is always -- is really about is how to trust your instrument? But one of the most important things, I think, is always to run your experiments with a reference material using the same conditions that you're using for your measurement. That way, you always know that your instrument is right. Don't trust the methods that are built in. They might use different parameters. So always run them under -- using your pan and gas and your heating, right, that you're going to use for your measurements, and you can run them and then verify the performance of your instrument. So there's a question here. What reference standards do you recommend for a TGA if testing over the entire temperature range? I pasted a link to a -- to one of our -- to our chart. I think I've got a copy of it up here behind me actually, that has a list of reference substances on it that you might want to check out. Just holding it up here, but you can also print out a copy. I'm going to -- yes, for the [indiscernible] temperature, there are a few element are mentioned on this chart. So the ones that we normally use, they have nickel and [indiscernible], that's at 357 and 748. And then isotherm, you can also use at 144. Those are 3 theory point standards that can be used. There's also cobalt. Well, iron is at 768, and cobalt is at 1,121 degree C. So -- and then if you have a TGA/DSC, of course, melting point standards are going to be much more accurate, if you have a simultaneous instrument. So another question, how often does the DSC need to be calibrated? Good question. That's a million-dollar question. That depends on your own quality procedure and your own -- we can make a recommendation. I think the reference manual says maybe once a month, it's to check the calibration, but really, it only takes 5 or 10 minutes to run an indium check in a DSC, for instance, to just -- remember, a calibration is a verification only. So that way, you'll know how far off you are. And how often you need to do it? Depends upon your tolerance limits. If you and your quality system set very tight limits for accuracy, you will spend more time adjusting an instrument. That's probably a mistake that I made in school. I spent -- this is 25 years ago. I spent a lot of time trying to get perfection, which is hard to achieve. But if you know that your product won't be affected if the calibration is, say, within plus or minus a degree, for instance, if that won't make any difference to your product, there's no reason to calibrate your instrument any tighter than that. And you will find that your instrument would very seldom be out of adjustment if you ran a check. So just general recommendation might be a monthly, but some people I've seen run it weekly. Some people run it daily. I've seen, in the extreme case, there is one customer who really didn't trust their instrument. They chose to run a calibration check in between every sample, just so they could document. That between every sample, there was -- that their instruments giving the correct result. So there's another question, any recommendation for long-term downtime of a DSC before shutdown and when bringing it back online? So that's -- again, checking the calibration of your DSC is pretty easy to do. You can run a couple of 10-minute experiments maybe to check it at both ends of the temperature range that you're using. So if you are going to take it down for an extended period of time, it's always -- it never hurts. It's easy enough to do a calibration check or verification. If you are going to bring it down from a powered off-state, I usually recommend letting the DSC and the cooler run for at least 20 to 30 minutes, and then run a couple of experiments to let it warm up, maybe just do a pre-indium check first or pre-melter indium sample before you check and verify the calibration is accurate. The instrument is giving you good results. How many times can you reuse standards, indium, for example? So probably depends more on the certificate more than anything else because you're -- if it's a certified reference material, it will have an expiration date. Practically speaking, you can -- I've kept -- the indium that I normally use -- granted, I'm not working in a regulated environment or anything like that. I've got an indium standard, kept them for 10 years, and they'll still give the same results as new. A trick that somebody gave me -- in most cases, I said indium doesn't normally oxidize or change. It could form an alloy with the pan. But in that case, if formed an alloy, you would see a decreasing trend. Every time you ran it, the temperature would go down just a little bit. A good trick. Another thing that I was taught is to keep 2 reference pans or 2 standards available, 2 different pans, 1 with indium we use regularly and 1 with indium or whatever calibration or substance you're using. You might be using less often. As long as those 2 standards agree with each other, both of them are good. Very -- it would be very unlikely that they would both go bad at the same time and by the same degree. So that's a good tip. I think that I was taught that I like a lot, just to make 2 standards and every once in a while, check them both. And if they're an agreement with one another, then both standards are good. Some other standards might not last as long. Zinc is a higher temperature standard. It will oxidize more on the surface. But practically speaking, I see very little difference in that over time as well. But you should prove this to yourself. You're welcome. Do we have any other questions? All right. As I said that when I pasted it above the links, one of the top link I put in was a list -- was a link to a table of reference materials and the values that you can use for calibrating purposes. There are some other useful links up there as well, too. So thanks, everyone, for attending. And is there a survey coming up at the end, Patti or Renee?

It's been added to the chat. So we would appreciate if you go ahead and fill that out. Sorry, Renee. Go ahead.

No, you're good. I reposted it. Let me see if that link works. I'll just go ahead and repost it again for you guys there.

All right. Well, thanks, everyone, for your kind attention today and for letting us know how we did on the survey. We do appreciate it, and thanks again.