diode rectifier-amplifier meter

diode rectifier-amplifier meter

[¦dī‚ōd ¦rek·tə‚fī·ər ′am·plə‚fī·ər ‚mēd·ər]
(electronics)
The most widely used vacuum tube voltmeter for measurement of alternating-current voltage; has separate tubes for rectification and direct-current amplification, permitting an optimum design for each.