News. Testing Labs Weighing and Analysis in the Laboratory. EMPA Scientists Beyond Scratching the Surface

Transcription

1 Testing Labs Weighing and Analysis in the Laboratory 3 News EMPA Scientists Beyond Scratching the Surface EMPA is an internationally recognized research, development and service institution for materials science and technology. METTLER TOLEDO s moisture analyzer is an important fixture in their Dübendorf labs in Switzerland, helping them to meet the industry s demand for novel surface coatings. Coatings as Hard as it Gets The engineering of novel lacquers and surface coatings takes place in the nanometer range. Specifically required property profiles of surface materials, for instance extremely hard coatings for snow boards, cellular phones or industrial tools, combined with optimal frictional properties, can be obtained by integrating nanoparticles. EMPA scientists have gained insight in the mechanisms of the nano world and are able to produce a wide spectrum of nanopowders with well defined properties. In collaboration with industry, these latest findings and technologies are transferred into the development of new functional surface coatings. Moisture determination, in particular, plays an important part in the characterization of nanocomposite lacquers. Moisture Analysis as Gentle as it Gets METTLER TOLEDO s halogen technology allows fast and uniform sample heating for highly reproducible results. Some lacquers, however, form a skin during the fast heating process to obstruct the release of water and solvents. To cope with this challenge, the gentle drying mode of HR73 offers gradual temperature increase to heat the lacquer evenly from outside to inside by heat convection. With this smart solution, precise and repeatable determination of moisture content is ensured. For more features of the HR83, the HR73 s successor, go to }

2 DSC Analyzing Petroleum Wax According to ASTM D 4419 The ASTM D 4419 standard describes the conditions for measuring transition temperatures of petroleum waxes using differential calorimetry scanning (DSC). The transition temperatures provide petrochemical testing laboratories with important information on the quality of petroleum derivatives while the melting peak assists with the characterization and analysis of petroleum wax. Publisher Mettler-Toledo AG Laboratory & Weighing Technologies Im Langacher CH-8606 Greifensee, Switzerland Production Segment Marketing LAB Switzerland Technical articles Mettler-Toledo AG Laboratory & Weighing Technologies Analytical Instruments DSC is a fast, convenient and reliable thermal analysis technique used for determining the characteristic temperatures of a wax during transitions. The highest temperature transition is a solidliquid transition associated with complete melting. This transition provides a guide for choosing the most suitable storage and application temperatures. The solidliquid temperature transition yields information on the properties of the solid, such as hardness and blocking temperature. Determining Transition Temperatures Using DSC The DSC 1 is a fully automated and versatile tool that can be used to accurately measure transition temperatures of oil/wax mixtures. The example in Figure 1 demonstrates melting behavior. Five known and two unknown oil/wax mixture samples were pre-melted, stirred and cooled under controlled conditions. Samples were then heated from 60 C to 80 C at 5 K/min to determine the transition temperatures. The results were evaluated using the STAR e software and displayed typical melting behavior with peak melting temperatures between 46 and 57 C. The two unknown samples could also be identified as the DSC curves were characteristic for petroleum wax. The oil content of the two unknown samples was estimated using a calibration curve. This was done by plotting the five known oil contents as a function of the melting enthalpy. Figure 2 shows the excellent linear relationship between the oil content and the overall melting enthalpy. The unknown oil contents of samples 6 and 7 (Figure 1) were estimated to be 22.4% and 0.6%. The fully automated and versatile DSC 1 is an excellent tool for measuring transition temperatures of petroleum wax. With the wide temperature range, accuracy and outstanding measurement performance, the DSC 1 offers great benefits to the petrochemical testing laboratory. } Subject to technical changes. Mettler-Toledo AG 08/01 Printed in Switzerland. 2

3 Figure 1. Melting of oil/wax mixtures. DSC 1 Figure 2. Correlation of enthalpy versus oil content in oil/wax mixtures. 3

4 Excellence Plus Balances Safety in Construction Guaranteed by METTLER TOLEDO s Excellence Plus Balanc The IGH (Civil Engineering Institute of Croatia) is the leading Croatian company specializing in civil engineering research and development. They provide expertise and recommendations to construction companies in order to ensure that construction work is carried out in adherence to safety guidelines. They rely on METTLER TOLEDO s Excellence Plus balances for all their research tests. Only the Best Instruments for Experts The department for concrete and masonry structures at IGH in Zagreb is responsible for ascertaining the reasons behind construction errors and for developing specific solutions to improve the strength and lifespan of buildings. The uptake of moisture content, construction material density and gravel particle size within cement mixtures are important quality parameters here and the IGH relies on several METTLER TOLEDO Excellence Plus precision balances when testing these aspects. Moisture Uptake is a Critical Factor To measure the moisture uptake of construction material, an XP8002S/M precision balance (approved version) with a weighing capacity of 8 kg and readability of 0.01 g is used. Initially, the test material is cut into the appropriate sample sizes and then dried in a drying oven with subsequent weighing to determine the dry weight. Secondly, the sample is immersed in a water bath to a depth of approximately 5 mm and weighed again after a defined period of time. This whole process is repeated 6 times and the total weight gained is equal to the maximum possible water uptake of the sample. For this application, the IP54 in-use classification of the XP balance entirely protects the instrument against water and dust intrusion which is especially beneficial when handling moist construction material. In addition, the intuitive and simple balance operation is of particular value for the laboratory staff. Density Determines Quality of Construction Material The density of construction material is determined by applying the Archimedes principle (buoyancy method). The XP10002S/M (approved version), with a weighing capacity of 10 kg and readability of 0.01 g, is used for this measurement. As some of the tested construction material can reach rather large proportions, weighing is performed via under-floor weighing using a special hook beneath the balance. For density determination the samples are hung underneath the balance, initially weighed in air and subsequently in water by completely immersing the sample into a water bucket in order to determine the density. This can be subsequently determined from the difference in weight. Thanks to the builtin density application, the user is guided through a step by step process in order to automatically and reliably calculate the density value. Sieve Analysis of Bulky Materials To examine material quality based on particle size, a sieve analysis is conducted using XP32001L/M (approved) precision balances with a weighing capacity of 32 kg and readability of 0.1 g. Thanks to the large weighing platform of 360x280 mm, sieves with a diameter of up to 400 mm can be used. The operator can monitor the remaining gravel material quantity on the balance screen as an 4

5 Start es cutting drying (24 h) weighing absolute weight value and as a percentile value with the integrated percent weighing application. The IGH Institute purchased a total of 10 Excellence Plus balances in All balances are maintained and tested annually by a METTLER TOLEDO service team to guarantee a consistent optimal weighing performance. according defined time Number of workflows in waterbath (overall 25 h) Time interval } overall 6 times backweighing Loop finished? Calculation with graphic analysis End 5

6 LiQC Multi-Parameter Analysis: The Next Stage in Automation Revolution Modern laboratories are already automated but a recent new development is taking this to a new level: Combining multiple parameters into one analysis station further improves accuracy, productivity and security. METTLER TOLEDO s LiQC allows the simultaneous measurement of up to four parameters often analyzed in the quality control of liquids. Combining Parameters for Improved Productivity Laboratory automation has been a constantly improving process over the past decades. It started in the 1970s when instruments such as auto-titrators or digital density meters started to replace cumbersome manual apparatus such as glass burettes and pycnometers, notorious for their lack of accuracy and high operator dependence. Productivity improvement was addressed in the late 1980s, when the first auto-samplers allowed the analysis of a series of samples without operator interference. Current automation trends go one step further. So called multi-parameter systems offer the automatic determination of multiple parameters in the same sample and transfer results directly into a laboratory information system (LIMS). This, of course, revolutionizes sample through-put, reduces the amount of sample needed for testing and relieves lab technicians for other tasks. LiQC: Easier Quality Control of Liquids METTLER TOLEDO s LiQC system offers determination of density, refractive index, color, ph and conductivity from the same sample. As a computer based system it can be tailored to automatically recognize samples by bar code, chose an appropriate measuring method, analyze all the desired parameters and evaluate results according to specifications. It exports measured data into a freely configurable ASCII text file, making them available for effortless import into virtually any LIMS LiQC system for simultaneous measurement of density, refractive index and ph with barcode based sample identification. 6

7 system. For more sophisticated analyses, it even allows sophisticated computation of results such as polynomial fit for concentration determination in tertiary mixtures. Thanks to a very simple user interface, LiQC can be operated by scientists and non-scientific personnel alike. Forgotten Your Password? Biometric User Identification One of the most significant innovations within LiQC is its approach to user management. In regulated industries (pharma, cosmetics, food) full traceability of results is a must and therefore user tracking and user rights have to be managed by an analytical instrument. So far, this was accomplished by username/password combinations which had to be entered every time the instrument was used. LiQC follows a different route: It utilizes biometric data (a finger print reader) to unambiguously identify each operator. Users simply scan their index finger before measurement and the instrument automatically assigns predefined user rights and stores the user information with each result. This technology has never before been used in the analytical instrument industry and its application is patented by METLER TOLEDO. To summarize, multi-parameter systems constitute the latest revolution in analysis automation. LiQC offers; automatic determination of up to four parameters, many advantages in sample and result handling and the management of user identification in a novel and time saving manner by using a finger print reader. } 7

8 New Products and Technologies From METTLER TOLEDO METTLER TOLEDO delivers powerful solutions that simplify work in laboratories around the world. Combining our state-of-the-art technologies with our applicative competence, we have a strong value proposition to make: accurate results and productivity second to none. Weighing Solutions and Analytical Instruments Plug & Play Titration Sensors Demanding Applications, Easily Mastered A comprehensive range of 17 Plug & Play ph glass, platinum and silver titration sensors is now available. The sensors cover the entire applications spectrum from routine ph measurements to special titrations in difficult sample matrices. The sensor chip in the electrode head stores all relevant data which is automatically read into the titrator setup when the sensor is connected. The design has been optimized for faster response times and signal equilibration especially for use in testing labs. Filter Weighing with Micro Balances Precision to the Very Last Particle The new filter weighing kit for the MX/UMX balance from METTLER TOLEDO is the best solution for the gravimetric measurement of fine particles. Its robust stainless steel housing eliminates air turbulence and heat transfer, assuring faster stabilization times and improved weighing performance. The automated draft chamber and the SmartSens infrared terminal sensor facilitate each error-free and clean operation without the balance being touched. XP-K Ultra Load Line Comparator Balances Peak Performance up to 6000kg Weighing 1000kg or 6000kg accurately is a challenging task. With the new XP-K Ultra Load Line and its new MonoBloc weighing cell technology, peak performance can be reached easily. The dedicated centering device, Levelmatic, guarantees measurement quality and eliminates eccentric load deviation. Evaporation Trap Accurate Pipettes Day by Day For the occasional pipette performance check, simply convert the balance into a pipette check set-up within seconds. METTLER TOLEDO has recently introduced an evaporation trap for the XP26/XP56 microbalance as well as large evaporation traps (capacity 100ml) for the MCP system and for the WXT weighing module. By supporting uninterrupted pipetting, even for high-volume pipettes, the large capacity traps save the time needed to empty the waste vessel. Mettler-Toledo AG Laboratory & Weighing Technologies Im Langacher CH-8606 Greifensee, Switzerland Mettler-Toledo AG Analytical Instruments Sonnenbergstrasse 74 CH-8603 Schwerzenbach, Switzerland Your METTLER TOLEDO contact: For more information