{'fraction_non_alphanumeric': 0.021037868162692847, 'fraction_numerical': 0.009817671809256662, 'mean_word_length': 5.0, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Improved performance of a refurbished photoelectric autocollimator

An old photoelectric Hilger & Watts autocollimator (AC) has been modified at INRIM to perform accurate angle measurements on two axes in a range of ±250″. A CMOS camera was placed in the focus of the AC’s optical system and a software implemented in LabVIEW processes on-line the image of the reticle projected on the camera. The data acquisition is triggerable at a selectable frequency up to some hertz to allow synchronization in critical applications. The AC’s sensitivity was determined through a calibration with respect to the national angle standard. The combined standard uncertainty of the AC calibration results to be equal to 0.035″.