Power Vacuum Tubes Handbook, 3rd Edition

13Safe Handling of Vacuum Tube Devices

13.1 Introduction

Electrical safety is important when working with any type of electronic hardware. Because vacuum tubes operate at high voltages and currents, safety is doubly important. The primary areas of concern, from a safety standpoint, include

• Electric shock

• Nonionizing radiation

• Beryllium oxide (BeO) ceramic dust

• Hot surfaces of vacuum tube devices

• Polychlorinated biphenyls (PCBs)

13.2 Electric Shock

Surprisingly little current is required to injure a person. Studies at Underwriters Laboratories (UL) show that the electrical resistance of the human body varies with the amount of moisture on the skin, the muscular structure of the body, and the applied voltage. The typical hand-to-hand resistance ...