| The reading on the combustible gas indicator, shown in the illustration, is obtained by burning the vapor sample within the instrument. How is the flame prevented from igniting the vapor within the space being tested? |
| A) The test burn occurs outside the tested space. |
| B) A series of baffles within the instrument prevents a flashback. |
| C) The length and diameter of the sampling tube are designed to prevent a flashback. |
| D) Flame arresters are placed at the inlet and outlet of the combustion chamber. |
