Calibrating MQ2 gas sensor

Other Hardware Sensors
1

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?

2

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

3

Have you tried integrating the MQ2 with Arduino Uno