Page 51 - TesaKatalogen

E x ter n al M i c r o meters

Precision Measurement

Precision measurement requires the use of micrometers. In 1848, the first measuring tool
of this type was patented by the French inventor Jean Laurent Palmer as "calibre à vis
et à vernier circulaire" (screw caliper with a circular vernier). Today, we continue to make
external micrometers with these typical features. The introduction of the micrometer to
the mechanical world came about due to the visit of the two American engineers, Joseph R.
Brown and Lucian Sharpe to the Paris Exhibition in 1867. At that time, their attention was
drawn to Palmer’s invention, which greatly interested them. After some improvements of
Palmer's design, the product was manufactured on a large scale and marketed successfully
by the two partners. History repeated itself years later as TESA SA decided to manufacture
external micrometers, making them the first products produced by the company.

Whether for internal or external measurement, TESA micrometers are distinguishable for
their construction and quality. All our models respect the ABBE principle with the exception
of the models with large mearing anvils for the measurement of gear teeth for example.

Max. permissible errors State of the art machining tech-
niques are used for grinding the
Measuring range Maximum Number of interference µm micrometer spindles, to ensure
mm permissible fringes or rings extreme accuracy and a true
reproduction of the thread with
errors* negligible pitch deviations. For this
µm reason we can guarantee a very
low measuring uncertainty to our
0 ÷ 25 4 6 2 instrument users. TESA micrometers
25 ÷ 50 4 6 2 are designed to meet the most
50 ÷ 75 5 10 3 exacting demands. They are robust
75 ÷ 100 5 10 3 and ergonomically designed.
We offer an extensive range of
100 ÷ 125 6 3 micrometers, from a classic model
125 ÷ 150 6 3 through to micrometers for special
150 ÷ 175 7 4 applications, and also micrometer
175 ÷ 200 7 4 heads, complete sets, accessories
and all items needed for calibra-
200 ÷ 225 8 4 tion. They are available in analogue
225 ÷ 250 8 4 or digital versions, and also digital
250 ÷ 275 9 5 versions with results output.
275 ÷ 300 9 5

300 ÷ 325 10 5
325 ÷ 350 10 5
350 ÷ 375 11 6
375 ÷ 400 11 6

400 ÷ 425 12 6
425 ÷ 450 12 6
450 ÷ 475 13 7
475 ÷ 500 13 7

* Including the errors of the measuring element as well as any deviations in
the flatness and paralellism of the measuring faces, plus any errors due to
the flexing of the frame.

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