MQ Sensor drops voltage as opposed to raising it

I am using an UNO connected up with an MQ 131 O3 gas sensor. Using an led bar graph to visually display the sensor readings. Works great using sample codes and example wiring methods. But I have one problem. It is backwards (The voltage is reduced when gas is applied to the sensor.) Which means my led bar graph is fully illuminated at start up and then slowly turns off as gas is sensed.
My questions:

  • Can anyone provide me with a possible solution to this? The current code I am using is the Arduino Playground led bar graph example code. I have only modified the 1023 value to 255.
    -Also, I would much rather prefer these leds on the bar graph to be either on or off. Right now they are on many of the PWM outputs and the leds will flicker and pulse which looks very dumb. can this be compensated with some addition code to set each ouput to a specific value. When its value is reached it is fully on and when it is below its value it would be fully off?

The voltage ref. is around 3Vdc. If that means anything....

Thank you for you time and help!

The current code I am using is the Arduino Playground led bar graph example code.

That may be where you got it. But, now it's your code. If you want help with YOUR code, post YOUR code.

Also, I would much rather prefer these leds on the bar graph to be either on or off. Right now they are on many of the PWM outputs and the leds will flicker and pulse which looks very dumb. can this be compensated with some addition code to set each ouput to a specific value.

Yes. Fix your code. No see == no help.

The voltage ref. is around 3Vdc. If that means anything....

It would be more useful to know where that voltage is coming from, where it is going, and how you know that it is exactly "around 3 volts".