FAQ
What accuracy does the MVS2pro have compared to that of the gradient columns?
Measurement precision and uncertainty are very important issues in the execution of a measurement. In the case of the MVS2pro system, these data can be calculated directly during the measurement using the precision of the certified standard parameters we use to calibrate the system itself.
The values are beyond the possibilities of the old gradient columns and, in any case, they also depend on the electronic scales we use which is coupled to the system.
We recommend a Mettler with 5 decimal digits in order to obtain a 5.digit measurement such as 942.02 on which the uncertainty influences only the last digit by +/- 0,02.
The accuracy is excellent as we can use the same standard used for calibration by analyzing it again as if it was a sample, obtaining a value very close to that mentioned in the certificate. Also, in this case the deviation is around 0.02. All these values are obviously also influenced by the environment in which the system operates and by how the sample is prepared but we still can, with appropriate measurement procedures, identify the environmental component and the sample preparation component; easily distinguishing them and this obtaining a very reliable statistical validation of the system as a result, impossible to obtain with the old Gradient Columns.
What different approach to simple measurement is necessary to take with MVS2 pro compared to the Gradient Columns?
For HDPE, which is a polymer in which the density measurement is very important, we recommend to follow the ISO293 and method B that works with a fusion process in an hydraulic press and a cooling process down to 15 degrees/minute.
The critical point concerns precisely the cooling rate that causes the partition between the amorphous and crystalline phase in the polymer which, in this way, always occurs in the same way for the exact same sample.
The partition coefficient influences the density and is therefore a very critical aspect in the preparation of a standardized sample which is impossible to make for the measurement with gradient columns.
The different trustworthiness of the two methods is very evident since the standardization of samples practically does not exist with the gradient colums’ measurement.
What times and costs does the MVS2 pro system have, compared to those of the gradient columns?
Time is the key point that heavily differentiates our MVS2Pro system from the old gradient columns. In fact, while it takes from 4 up to 8 hours to obtain a reliable measurement with the gradient columns, with our new system it will take only 30 minutes of preparation and 2-3 minutes per sample for their analysis.
It must be said here that this data is often used to notice if everything is being produced as according to the product specifications.
These production plants are a continuous cycle where the time factor is decisive and with our MVS2pro system we decidedly meet the request of a fast productive chain.
What are the ideal sample size and shaper for MVS2pro?
We have the ability to generate or measure a sample of any shape suitable for the size of the Beker in which we carry out the measurement. The shape we suggest is that of a disk of 30 or 40mm, 2mm thick with a hole of about 2mm near an edge for coupling.
How is it possible to certify the MVS2pro measurement process?
The MVS2pro system has a validation procedure I would say very simple because, by providing the system with a standard certified by an internationally accredited body for mass, volume and density we are able to calibrate the system and use the same standard as if it was an unknown sample, thus detecting that the density value declared in the certificate is measured correctly.
We are also implementing a procedure in the system that for now can be performed with evaluations which are external to the system, with which we are also able to validate the sequence of measurements made on real polymer samples.
Is the MVS2pro operating proecss ISO compliant? Is the integrations into the company quality process easy or it necessary yo validate internal methods, usually difficult to generate?
The MVS2pro system allows you to follow more than one ISO procedure from sample preparation to measurement, it also allows, in this context, to calculate the measurement uncertainty that we will shortly enter as a data, calculated by the system. It is therefore very easy to integrate in a broader quality plan a measured data, starting from these solid standardized scientific bases, the process and the measurement itself.
Our system performs the measurement in compliant according to ISO1183 part 1 method A, instead of ISO 1183 part 2 which describes the method of gradient columns.
How much does the sample preparation and the influencer of the operator’s technical skills count in the measurement with MVS2pro?
Our MVS2pro carries out the measurement in a completely automatic way and it is therefore totally independent of the technical skills of operators: reliability of the measure regardless…
In this regard, we have also prepared a document that compares the two systems technically and mathematically to better understand what are the key points that differentiate the two.
Are there any limitations on the measurement range of the MVS2pro system?
Our MVS2pro does not formally have any limitations on the measurement range. In fact we can currently measure 780kg/m3 polymers from precious metals which have very low densities. We can also go below that value using the forced sinking technique.
Gradient columns, on the other hand, have objective limitations given by the minimum and maximum density value which corresponds to the density of the liquids used. It should also be taken into account that density values close to the expected maximum cannot be read, because in those ranges the measurements are unreliable.
What management costs does the MVS2pro system have?
The operating costs are very low compared to those of the gradient columns. In fact, the highest cost is that of the refueling of the gradient liquids that you can find in the columns. These liquids must be frequently refurbished because of the samples’ fragments inside or, for the most unfortunate reason, because they’ve been contaminated due to a break in the gradient, which is really fragile.
It should also be added that in addition to the management costs we have talked about just now, the gradient columns have recovery and stabilization times of 2 days.
Our MVS2pro system does not have any of these limitations. We use a Pure Liquid for the measurement and if it is low, the system notices it immediately and suggests a refill with the immediate restart of the measurements.
How does Ortelli technologies manage worldwide support?
The system was designed to operate according to high quality construction criteria.
We also thought of a design that could be supported remotely with the usual means, easily via the net. Now we are able to get to the internal controller through the PC that supervises it. Of course, this allows us to remotely control it. In addition we have the possibility to organize customized Live Webinar Demos both to introduce you to our system and to schedule training courses.