Calibrating MQ2 gas sensor

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

Vcc - 5V
GND
SIG - A2

I tested the calibration mentioned in http://www.seeedstudio.com/wiki/Grove_-Gas_Sensor(MQ2)#Measurement:_Approximation

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