Stabinger's virtual journey

THROUGH TIME

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1966

First Density Oscillator 1966

The first density measuring oscillator, which was built in 1966, had a hollow sphere on the front end which was filled with the sample and its natural oscillation was stimulated by means of a system of solenoid coils.

When he was research assistant at the Institute for Physical Chemistry of the University of Graz in the mid-1960s, DI Hans Stabinger was entrusted with the task of determining the density of liquids with highest possible precision with the pycnometer method. This work is difficult and time-consuming. Moreover, it requires large sample volumes. Thus Hans Stabinger was looking for alternatives and began to experiment with so called oscillating U-tubes, where basically the oscillations in its natural frequency of a U-shaped tube—which is for the most part made of glass, fixed at its ends, and filled with a sample—are displayed. The density of the sample can be calculated on the basis of the oscillation period of this object if the parameters of this oscillating object have been determined by measuring two samples with known density beforehand.
1967

DMA 02C

The first digital density meter, the DMA 02C was presented at the ACHEMA in Frankfurt, Germany, already in 1967.

Features: electromagnetically stimulated oscillating glass U-tube; then as now, with an inside diameter of 2 mm in a copper casing that was brought to the right temperature with an external liquid thermostat. A 100 kHz crystal oscillator served as the time basis, and a 7-digit meter as the output of the oscillation period. From this, the density of the samples had be externally calculated. Every decade of the counter required a circuit board in Eurocard format so that the entire interior of the housing was taken up by the counting electronics. The Nixie tubes, which worked like glow lamps were triggered by discrete high-voltage transistors. It was built and distributed by Anton Paar GmbH, and by Dr. Virius in the FRG, at a stiff price of 100,000 Austrian schillings. At the time, we believed we would achieve a measuring uncertainty of 0.000001 g/ccm, which missed the truth by the factor of 1,000. After all, we achieved the previously unrivalled precision of 0.000001 g/ccm.
1968

Glass Blowing Work of the Highest Perfection

August Höfler (aka “der Bürstl“) of Bartelt, Graz, one of our very first partners, contributed the glass blowing work for our devices with great personal commitment and phenomenal skills from the beginnings in 1965 until he retired. Thus he contributed essentially to the success of many projects.

1972

DMA 10

A simple density meter of the early 1970s with limited precision.

Feature: electromagnetically stimulated glass oscillator in a brass housing with external thermostatting. Using integrated components for the decade counters and the high-voltage triggering of the glow discharge tubes, we were able to build up the complete electronics on only one circuit board. The measurement values were displayed as period durations from which density had to be externally calculated.

DMA 60/602

First half of the 1970s: Separation of electronics (DMA 60) and measuring cell (DMA 602).

First-time use of a frequency multiplier in order to use a second measuring cell as the time basis for the first one so that very precise measurements of differences in density became possible. The period duration of the measuring oscillator was displayed as the measurement value on a numerical 7-segment LED display, from which density had to be externally calculated. The oscillating U-tube is enveloped in a glass sheath tube which is filled with hydrogen inside. The thermostat liquid of an external thermostat flows through it. Filling the oscillator casing with hydrogen caused the sample to adapt its temperature to the required temperature about 8 times faster.
1975

DMA 55

The first density meter with a built-in digital calculator.

A density meter with digital density output. The externally calculated device invariables to be entered via digit buttons. The measuring cell is similar to the one of the density meter DMA 602. Thermostatting via external fluid thermostat.
1980

Process Measuring Devices for Density and Sound Velocity

Density Measurement in Process Technology

Most of our measuring devices for laboratories have their equivalents in process measuring technology. The image shows a DPRn 427 measuring cell, which has been built since the early 1990s.

External Measuring Cell

Measuring cells were developed for specific applications, which were operated in combination with a standard laboratory device. For example, an external density measuring cell DMA 401W with an upstream heat exchanger is shown here.

1982

DMA 35

Early 1980s: Battery-powered portable density meter with direct display.

The calculation of density from the oscillator frequency was done by means of a sophisticated analogue circuit without a digital calculator, which was not yet available at that time. A folding oscillator was used as the measuring oscillator. The device was produced in large number and held its ground excellently against replicas from the Far East. Continuous development—above all in the electronics an in customer friendliness were the crucial factors. Anton Paar was awarded the Innovation Prize for this device, which was developed up to serial production in our working group.
1987

DMA 48

Digital density meter for laboratory use.

A device with a new appearance in a pressure die-casting frame. An improved calculator facilitated the calibration of the device, which was now a genuine stand-alone device with a Peltier thermostat. A full glass construction filled with hydrogen, which was equipped in addition with a magneto-dynamic testing and stimulation system, served as the measuring cell. This was the first time that compensation of the viscosity-induced density error was realised by shifting the phase angle between the stimulation and the testing signal. Its forerunner was the DM 46 device, already with a built-in Peltier thermostat and internal density calculation.

Our Own Company Building

We moved into the new company building in the summer of 1987.

Two years later, in 1989, Dr. Stabinger left Forschungsgesellschaft Joanneum and established his own company.
1988

DMA 38

Entry-level device for the measurement of density with award-winning design.

New edition of the DMA 10 device with new electronics. The idiosyncratic design we developed was honoured by the Austrian trade minister of that time, Josef Staribacher. The device was produced over a period of 20 years without any changes.
1991

AUSTROMIR-91

Our experiment in outer space.

We were asked to help out solving the problem of measuring the hematocrit level in the blood of an astronaut in zero gravity. We successfully developed a device on the basis of measuring sound velocity. It was successfully used by DI Franz Viehböck in the Mir space station during the mission.
1994

Blood Volume Monitor

A new method of measuring the hematocrit level in blood online.

Looking for new applications of measuring sound velocity, we came across the problem of measuring hematocrit, the level of red blood cells in the blood, directly in the dialysis tube. We were able to press ahead with the development of the apparatus so far that preliminary tests, in dialysis ambulances in Graz and Zürich, among other places, showed the possibility of flawless measurements. D. Schneditz verified the new method in a clinical study in Graz and New York. Fresenius Medical Care Bad Homburg, Germany, developed it into a device that could be used directly on patients.
1995

The Beer Monitor

In the Beer Monitor, a density and sound velocity measuring cell are arranged in the DPRn housing in such a way that the same sample stream flows through them.

In beer, for example, the alcohol and original extract content can be determined online from the density, the sound velocity, and the temperature of the sample. But this device is also used for analysing other ternary (three-component) systems.

1997

DMA 4500 / 5000

Early 1990s: a new generation of the density meter, with a reference oscillator and a Peltier thermostat.

A new generation of density meters, with a reference oscillator and a Peltier thermostat. Completely new electronic evaluation, graphical display, all software options possible at that time. The density measuring cell is based on the DMA 602 measuring cell but now with a reference oscillator as the time basis for the measuring oscillator, with the built-in precision thermometer Pt 100, oscillation stimulation via piezo elements at the bottom of the measuring oscillator, optical testing of the oscillator deviation, oscillation stimulation in the base and first higher-mode oscillation, and attenuation measurement for correcting the viscosity. Thermostatting is done by built-in Pelier thermostats.

DMA 35N

Portable density meter, also available in an explosion-proof version.

The “dog leash” design conceived by Hans Stabinger has proved effective in practice thousands of times, and has turned the DMA 35 into a big success. Along with high precision and practical handling, above all the ex version for use in explosive environments is an outstanding feature of the measuring device. It is also appreciated by winemakers and distillers, who can easily monitor the quality of their products with them. Measuring the acid density of lead-acid batteries is another important application—thanks to its explosion protection it is even possible in submerged submarines.

SVM Prototype Nr. 1

In 1997, we began to explore the principle of a new rotational viscometer.

Thereby, a rotor freely floating in the sample inside a rotating tube is held in the centre of the tube by means of the pressure difference in the sample, which is located between the tube and the rotor. The rotor is decelerated by an eddy current element. The difference in rotational speed of the tube and the rotor depends on the viscosity of the sample. With small sample volumes, precise measurements of an otherwise unparalleled viscosity range are possible in a short period of time.
1999

SVM Prototype No.2

The first series of Stabinger Viscometers.

The first build of a device working according to the viscometer principle. This version was already built by Anton Paar in small lots. Yet, fundamental flaws required fundamental improvements.

2000

DSA 5000

Combined measuring of density and sound velocity with the highest precision.

In the 1980s, we opened up a new area of determining liquid properties with a new method of measuring sound velocity. This development was reflected in the density and sound velocity measuring device DSA 5000 with a built-in DMA 5000 density measuring cell and a sound velocity measuring cell. Mere sound velocity measuring cells and combined density and sound velocity measuring cells above all for process management in the beverage industry, especially in breweries, followed. The picture shows a newer version of the DSA (Generation M design by Anton Paar).
2001

SVM 3000

A new, revolutionary viscometer.

With this device working in line with the new viscometer principle, we laid the foundations for our entire development of viscometers. The inclusion of our method into the US standard ASTM under D7042 was a major success.
2007

DMA 35 V3

DMA35N, the portable density meter tried and tested thousands of times, is re-engineered.

A portable measuring device with completely re-engineered electronics and software compared to the tried and tested DMA 35N device.
2009

DMA 5000M

High-end laboratory density meter Generation M.
Picture: Wikipedia (Author: Antonpaar) under Creative Commons Attribution-Share Alike 3.0 Unported License.

New edition of the DMA 5000 density meter based on Anton Paar GmbH’s design requirements. The filling error detection and the camera supplement the measuring technology that has already tried and tested in the DMA 5000 Classic. The shown picture can be found at Wikipedia under the Creative Commons Attribution-Share Alike 3.0 Unported License.
2011

DMA 500

Portable density meter with Peltier thermostat.

New methods of oscillation stimulation encouraged us to adapt oscillator systems that we had previously only used in the area of process measuring also for laboratory measuring devices. At first, we did not achieve our initial aim—to develop a small portable density meter with a measuring uncertainty of less than 0.0001g/ccm. As all work on the electronics and the housing was ready for serial production we decided to make a virtue of necessity and to replace the already slightly out-of-date 3-digit device DMA 38 with the DMA 500 device, which we hadn’t planned initially.
2013

DMA 36

Portable instrument for measuring density with an oscillating metal tube.

For fast and precise density measurement, the very small density measuring cell of a diameter of only 14 mm is submerged in the sample, and filled with it. Due to the thus well-defined temperature, we were able to reduce the measuring uncertainty compared to the DMA 35 device by a factor of 5 to 10, and the measurement time too. It is sold by Anton Paar under the trade name “Snap 50”.
2014

Separation from Anton Paar The Beginning of a New Era

The cooperation with Anton Paar GmbH, which had lasted for tens of years, ended on 16 July 2014.

Anton Paar may still build and sell the instruments for measuring density and the speed of sound developed by us, as well as the Stabinger Viscometer, under licence. Nevertheless, the exclusive licence will expire by the end of January 2018. As from this date, our technology will be marketed with a new partner.
2015

The Future

The team of Stabinger Messtechnik is looking forward to future challenges.