Almotacén or fiel almotacén was the name of the inspectors of the Andalusian markets and workshops whose position as a public official increased in responsibility and autonomy from the times of the emirate of Córdoba (8th to 10th centuries) until their figure disappeared in the 2nd century. The DLE preserves that word to name the public employee who contrasted weights and measures, and includes as ancient uses that it also designated the butler in charge of the royal treasury and, in Morocco, the official who was in charge of monitoring the markets and indicating the price of merchandise every day.[1]​.

The word derives from the Hispanic Arabic almuḥtasáb, and this from the classical Arabic muḥŏtasib ("he who wins so many before God with his care for the community").[1]​ It was a figure brought from the Arab souks. He was in charge, under the orders of the Zabazoque, of reporting non-compliance with the ordinances. Its main functions were the control of weights and measures, setting prices and cleaning and urban planning. However, this trade gradually acquired the functions of the zabacoque, until the almotacenazgo became a voluntary and unpaid position, and became specialized until it even required (in 1086) to be alfaquí, thus needing the necessary legal knowledge.

The figure spread throughout the Spanish-Christian kingdoms with the names of almotacén, fiel del fuego or almotacín (mostassà or mostassaf in Catalonia and Valencia);[2]​ as those who were in charge of monitoring and verifying the exact adjustment of weights and measures in public transactions, especially in the markets. They acted ex officio or at the request of anyone who considered that the weight instruments had been modified. They also dealt with currency checking: weight and counterfeiting. His office was called fielato, a name that was also given to the entry control and toll collection posts that were at the gates of the cities until the middle of the century.

They were common in Al-Andalus, the kingdoms of Castile, Murcia, Aragon and Valencia, and in many cases municipal ordinances regulated their activity in each town "Villa (population)"). Given the differences in weights and measures between kingdoms, and even between different cities, they had to be familiar with the most common ones.

The figure does not disappear until the century.

• - Reweighing.