Weigelin E, Jessen K
Klin Monbl Augenheilkd. 1981 Jul;179(1):1-12. doi: 10.1055/s-2008-1057249.
After a survey of international developments in the standardization of tonometers since the introduction of the Schiötz tonometer in 1905, the bases for the calibration of tonometers are explained. Reference is made in particular to the criteria for comparative clinical measurements of tonometers in official acceptance tests. A description is given of all tonometers which have been approved for calibration in the Federal Republic of Germany so far, and of the test instruments used for calibration by the responsible authorities. Two pneumatic test instruments are also described, and the results of clinical examinations with them are mentioned. In conclusion, the prospects for international efforts to harmonize the standardization of tonometers are described.