The Permanent Exhibition “Weights and Measures in Portugal” is located in a rectangular room accessed from the entrance hall of the Museum and is organized in order to allow its visitors to follow the evolution and the history of metrology in Portugal. 

We can find, in a presentation that is based on a chronological logic, artifacts that take us back to medieval times, folloed by some representative standards of the various metrological reforms that took place in our country at the beginning of the Modern Period. Then we see the standards and measures of the Decimal Metric System and bibliographic and pedagogical material used for its promotion and dissemination, and, finally, we arrive at the Metro Convention and the replicas associated with the national standards of the meter and kilogram that, in the 19th century, came to Portugal. 

The vast majority of the pieces presented here were part of a unique exhibition in which they shared the same physical space with those currently found in the adjoining room, where we can see the Balance of the Casa da Índia (House of India). 

The inauguration, in 2016, of the new space of the Museum, allowed the Permanent Exhibition to be autonomous. The title is faithful to the original “Weights and Measures in Portugal” Exhibition. While maintaining an evident complementarity with the remaining material displayed in the adjoining room, the Permanent Exhibition assumes a unity and uniqueness that stems from its concentration in an autonomous area, in which the sequence of the exhibited pieces helps to build a historical, multi-century narrative, that allows visitors to understand the evolution of the measurement systems used in Portugal since the foundation of the country.