TESA CELEBRATES ITS
th 75 ANNIVERSARY
Since its origins, 75 years ago, TESA has distinguished itself by combining traditional craftsmanship with innovative designs to become a market leader and world renowned brand in the dimensional metrology sector.
When Jean-Georges Müller became director of Téléphonie SA, branch of Autophon AG, in a small workshop in Renens in 1941, he took bold decisions that would set the path for the TESA brand to become synonymous with precision measuring instruments.
Téléphonie SA factory in 1941
Téléphonie SA supplied telephone equipment for Autophon AG and radios for Steiner SA, two Swiss companies. The same year the company received an order from a customer for 8000 micrometers. The successful execution of this order resulted in the company diversifying into the manufacture of other mechanical measuring instruments such as vernier calipers, vernier height gauges with scribers and angle protractors.
Mechanical Ingenuity Already in the first years from 1942 till 1957, the company distinguished itself by developing innovative measuring instruments with patented mechanical designs.
The first major success was the IMICRO, a self-aligning and self-centring internal micrometer. Launched in 1945, it revolutionized the way precision bores were measured. The unique feature of this instrument was a high-precision spiral machined into its measuring cone designed for 3-point contact with a bore. In effect, this instrument still today is the only that respects the ABBE principle where the measuring system is in line with the points to be measured, thus ensuring a high measuring certainty.
IMICRO measuring head IMICRO measuring bore
With its focus on metrology and the collaboration with Autophon AG ending, the company changed its name from Téléphonie SA to TESA SA on May 1945 with its well-known three-triangle brand logo.
TESA factory in 1941
The IMICRO would be followed by a series of instruments that would help improve measuring certainty in dimensional metrology.
The TESAMASTER (an improved version of the earlier MICROMASTER), a micrometer developed in 1951, combined analogue, digital and vernier readings to provide parallax-free reading down to 0.001 millimetres. For the first time, there was a hand tool that had a resolution of one micron.
TESAMASTER
This would also be the start of a new era where TESA engineers developed mechanical systems for digital displays, which would be used in other instruments.
A year later, in 1952, the company launched the TESATEST (later renamed as TESATAST), a lever-type dial test indicator today widely used in workshops for determining position deviations as well as runout errors. The special feature of this instrument was that it was truly anti-magnetic with bi-directional measuring and automatic reversal inside the movement.
TESATAST application for centring a bore on a machine
The TESATAST would soon become an indispensable tool in workshops and an integral part of many machine operators’ kits.
One of the problems encountered in workshops was the measurement of large diameters to a high level of accuracy. Micrometers with large frames were used but they required a high degree of skill for such measurements.
TESA micrometer application for measuring a large shaft diameter
In 1957 TESA developed a solution for internal and external measurements of dimensions in excess of several metres. The UNIMASTER, a patented design based on comparative measurements, consists of a measuring element, a calibration frame and precision extensions. Its application range could be extended to several metres by simply adding extensions to the measuring element, which has a built-in lever-type dial test indicator to establish of the culmination point of a diameter. This instrument is capable of measuring diameters of several metres with a high precision.
UNIMASTER application for measuring a large diameter
Over the years TESA has been continually improving its product designs and manufacturing processes so that instruments such as the UNIMASTER are still being used for measuring large dimensions.
In 1962 TESA moved to its present location in Renens where it is now based. The new location, consisting of a three-storey office building connected by two passages to a large factory hall, marked a milestone in TESA’s history. The company’s sales had been increasing due to the efforts of its worldwide network of subsidiaries and agents. It now had a showroom, a canteen and training facilities for receiving agents and their service personnel.
TESA factory in Renens
In 1972 TESA developed the CCMA dial caliper based on a rack-and-pinion system with a patented gear shock proof system.
TESA CCMA dial caliper
The immediate success of this dial caliper would have an impact on TESA’s manufacturing operation. The company had to expand its manufacturing facility and set up its first production line to manufacture the CCMA dial caliper to meet market demand,
Digital Innovation During the early sixties, new technologies such as pneumatics and electronics were finding application in metrology. TESA took the strategic decision of opting for electronics instead of pneumatics. Based on this decision, TESA embarked on developing inductive probes and electronic amplifiers.
In 1961 the company launched the GT 10, an inductive probe designed to convert the slightest axial movement into an electronic signal. This probe could be attached to either analogue or digital display units.
Apart from high precision measuring applications such as the calibration of slip gauges, such probes are widely used in multi-gauging inspection fixtures. Today TESA has a wide range of inductive probes as the GT 21 – the successor to the GT 10 – has become one of the market leaders in its category.
GT 10, probe with GN 22 amplifier
TESA GT 21 probe
TESA’s mechanical expertise resulted in a sensor with a high degree of repeatability. A ferrite core moving in an electric coil generates an electronic signal. The measuring bolt connected to this core is in a ball cage guided by an anti-rotation system. It is the combination of high precision components and robust construction that ensures that the probe has a long life.
Fixture with GT 21 probes for inspecting a caliper frame
TESA would become a supplier of probes as well as electronic amplifiers, and controllers required for multi-gauging inspection fixtures and inspection machines.
Apart from axial and radial probes, TESA also launched the GT 31 lever probe with inclinable lever for measuring in two directions. There is also a digital version of the mechanical TESATAST lever-type test indicator.
TESA GT 31 lever probe and dial gauge
In 1981 TESA celebrated its 40th anniversary by launching the Micro-Hite, a height gauge designed for surface plate measurements.
The special feature of this height gauge was that its software enabled measurements in two coordinate directions. Since sixty percent of all three-coordinate measuring machine measurements are carried out in two coordinates, the Micro-Hite provided a low-cost solution for many workshops.
From left to right, Stefan Ruh, TESA Managing Director and Blaise Vuille, Sales and Marketing Director with TESA Micro-Hite
Over the years, TESA has expanded its range of digital height gauges and this product group contributes to a significant part of its business volume. Along with height gauges, TESA also pioneered in developing digital calipers.
TESA’s first electronic caliper, the Digit-Cal 1, launched in 1979, incorporates a mechanical rack-and- pinion system and a LED display.
TESA Digit-Cal 1 first electronic caliper (1979)
It was followed by versions that used glass, capacitive and magnetic scales. The latest workshop models offer complete IP 67 protection against liquids and dust. The connection is assured through cable or wireless connectivity.
TESA TWIN-CAL caliper with TESA wireless transceiver
Since its foundation, TESA was constantly innovating in developing instruments and systems which combined mechanical craftsmanship with technical innovation. In 1995 it obtained ISO 9001 certification as a further step towards ensuring quality in design and manufacturing.
Progressing towards the 4th industrial revolution - Industry 4.0 Hexagon, a Swedish company, acquired TESA in 2001 and the company was presented with new challenges.
Hexagon’s division, Hexagon Manufacturing Intelligence, is the world’s largest manufacturers of three- coordinate measuring machines (CMMs). TESA was assigned the task of developing a touch trigger probe for these machines and this product has now become a standard supply on such machines.
TESA touch trigger probe equipped with a styli for CMMs
“Today TESA is part of Hexagon Manufacturing Intelligence, a leading metrology and manufacturing solution specialist whose mission is to enable customers to improve productivity while enhancing product quality,” says Stefan Ruh, TESA’s Managing Director.
All products in the Hexagon Manufacturing Intelligence portfolio support this objective in three areas:
1. Sensing: acquiring and logging accurate measurement data 2. Thinking: transforming that data into actionable information 3. Acting: applying corrections to the manufacturing process based on this information
“TESA’s products integrate seamlessly into Hexagon’s complete manufacturing solutions,” adds Blaise Vuille, TESA’s Sales and Marketing Director.
In effect, the group has the tools for implementing Industry 4.0, which is the current trend of automation and data exchange in manufacturing technologies. The basic principle of Industry 4.0 is that by connecting machines, work pieces and systems, factories can create intelligent networks along the entire value chain that can control each other autonomously. This new dynamic will create what has been called a "smart factory".
The new range of TESA’s calipers and probes incorporate wireless transmitters so that their measuring data can be instantly transmitted via networks to computers for processing.
TESA’s own manufacturing plant uses this technology for ensuring quality control in its production. The factory, organised into manufacturing cells, looks more like a laboratory than a production unit.
During the last few years, Hexagon has invested heavily in modernising the plant with new machines and an automated surface treatment system. Equal importance is being given to product development as well as production.
TESA factory in 2016
One thing is true. Jean-Georges Muller’s philosophy of combining traditional Swiss craftsmanship with bold innovation still holds good for the company. The challenge now is to give new life to its range of inspection equipment through connectivity in the spirit of Industry 4.0.