Trouble with EPA particle detector project PPD42NS sensor

This is a project that uses a PPD42NS sensor. The project details can be found here. The code is here.

I am having a problem that the state of the LED's is not changing. I did the usual of blocking the beam path and there was no change. I do not know if the problem is something stupid; however, I have looked the project over carefully, or if the sensor is bad.

How should I test the sensor?

I am looking for something like, with a 5V input, the voltage at pin X should be X volts when the sensor is working properly.

I hope you have ignored the stupid instruction of using a 9volt (PPP3) battery to power an Arduino, three LEDs, an a 90mA dust sensor.

Yes, once I saw the sensor had a restive heater, the 9v battery made no sense. I am running it off a wall adapter