Fluke 8000A is desk-top 3½-digits low cost multimeter with power supply. It has been purchased in 1975 and never
calibrated. Accordings the operational manual, the errors of ac ranges should be ±0.5% from readable value
(45 Hz až 10 kHz) and 1% at frequences 10 kHz to 20 kHz. Input impedance should be 10 MΩ.