Advanced Qualification · A-003 Measurements · A-003-004-004
If a frequency counter with a time base accuracy of +/- 0.1 PPM (parts per million) reads 146 520 000 Hz, what is the most that the actual frequency being measured could differ from that reading?
- A 14.652 Hz
- B 0.1 MHz
- C 1.4652 Hz
- D 1.4652 kHz
Correct answer: A — 14.652 Hz. From the official ISED question bank, verified word for word.
Why
A time base accuracy of plus or minus 0.1 parts per million means the error is 0.1 for every one million hertz of the reading. The full explanation — and one for every question — is in Pro.
Practise this section
Measurements: meters, oscilloscopes, counters, signal generators, and what a reading actually tells you.