Introduced in the late 1950s/early 1960s, the GE H-7 was designed to detect leaks in refrigeration systems using halogen-based refrigerants like R-12, R-22, and R-134 (AKA Freon). It uses a halogen diode detector, in which halogens modulate the flow of alkali metal ions between two platinum electrodes.
0:00 Introduction
0:54 External Features
2:04 Setup and Calibration
4:15 Internal Components
4:53 Internal Disassembly
5:25 Halogen Diode Operation
7:48 Notes on Operation
8:36 Amplification and Balancing
9:40 Other GE Detectors
10:56 Outro
SOURCES
https://www.leybold.com/en/knowledge/vacuum-fundamentals/leak-detection/halogen-leak-detectors
https://www.ebay.com/itm/381571590126
https://vtda.org/docs/other/GE_Type_H-10_LeakDetector_OperationService.pdf
https://patents.google.com/patent/US3991360A/en
https://patents.google.com/patent/US2806991A/en?oq=+US+2,806,991+1957
https://patents.google.com/patent/US2550498A/en?oq=US+2,550,498+1951