{'fraction_non_alphanumeric': 0.012772351615326822, 'fraction_numerical': 0.006010518407212622, 'mean_word_length': 5.434782608695652, '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}}
Application of electro-optical holography to the measurement of strains at high temperatures

The measurement of strains at high temperatures has become a very important field of research. Advanced technology applications such as structures for high speed aircraft and high efficiency thermal engines are examples of areas requiring measurements of strains at temperatures well above the capability of present day strain gage technology. In a recent paper by one of the authors1 references on the application of optical techniques to field measurement of strains at high temperatures are given. Of the different techniques that are used, speckle and holographic interferometry are of particular interest. Both techniques are remote sensing and do not require elaborate preparation of the surfaces being investigated. From the view of practical applications the use of TV cameras for recording purposes and electro-optical data manipulation and processing are of great interest. Simplicity in handling the recording process, speedy data collection, and automatic data processing are the main advantages of using electro-optical methods. Some more developments in this field can be found in Reference 2-6. Reference 4 contains quantitative results proving the feasibility of making accurate measurements at temperatures up to 1000°C.