Question

How much memory (in bytes) would be required to store 20 seconds of a sensor signal by an 8-bit A/D converter, which can operate at a sampling rate up to 100 kHz, assuming
a) Sensor output with maximum frequency of 18 kHz sampled
b) We are measuring ECG signals for heart failure detection.
c) We are measuring EEG signals for seizure detection.
d) We are measuring temperature of a 1000-liter water tank for a process control.
e) We are measuring vibration signal of a car engine for engine diagnosis .

Answer 1

Answer :- If we have the maximum frequency component of the application, we can find the minimum memory requirement.

a) The maximum frequency of the sensor output is 18 kHz, hence the minimum sampling rate is 36 kHz. It means, we have 36000 samples per second.
Each sample having 8-bit, so for 1 second samples, total number of bits = 36000*8.
So in 20s, total number of bits = 36000*8*20 bits.

Hence the memory required in bytes is-

b) The maximum ECG frequency is 1 kHz. Thus in 20s, the number of bytes needed is-

Dear student, please mention/comment the maximum frequency component of each in c, d and e. The process is same for all. Thank you.