Arduino showing constant readings in analog pin without anything connected to it

[jerrylongnose]

hey there,
i have connected my arduino nano to my pc and it is showing constant pulsated readings without anything on the analog pins.
after connecting the sensor the intensity of the readings drop but the pulsated reads continue.

int eV = 0;
int eP = A2;

void setup() {
  Serial.begin(9600);
  // put your setup code here, to run once:
  
}

void loop() {
  eV = analogRead(eP);
  Serial.println(eV);
  delay(10);
  // put your main code here, to run repeatedly:

}

this is the pulse without my sensor

this is the pulse with my sensor

the frequency of the pulses are same.
this is altering my desired results of the emg sensor, it dosen't change if i move my muscles.
i have tried using arduino uno and mega too.
i guess this is a usb driver of some sort. gimme your opinions and solutions please.

[gilshultz]

Actually it is working as it should. It is displaying what it is getting. You need to lower the input impedance with some form of load and it will settle down. I will take a SWAG and say that looks like radiated signal from a switch mode converter such as a power supply.