but wasn't compiled or tested!
No, it wasn't!
return analogRead(sensorTHERMOMETER * scaleTHERMAL[glow])[/glow];
:o
Don't you need to move one of the sensor pins?
float voltage = readVoltage();
Serial.print("The voltage is ");
Serial.println(voltage, DEC);
Trying to print a float to ten decimal places is a waste of time.