Calibrating MQ2 gas sensor

I am using the MQ2 gas sensor with Arduino UNO and have made connections as follows

Vcc - 5V
SIG - A2

I tested the calibration mentioned in

My results are

  1. R0 = 1.45
  2. ratio = range from 8-10...Thus shows Air (from Graph)

My query:
The default position of the resistor pot a it shows different RO values at different resistor settings but the answer is around the same range
For better accuracy, What is the default position?

The Seeed people are very responsive on their forums. I would suggest asking there.

Have you tried integrating the MQ2 with Arduino Uno