What is the purpose of a draft gauge in a combustion appliance test?

The purpose of a draft gauge in a combustion appliance test is to measure the pressure difference between the inside and outside of the appliance. This measurement is crucial because it helps assess the efficiency of the combustion process and the proper operation of venting systems. A correct pressure differential ensures that combustion gases are being effectively drawn out of the appliance and that there is a sufficient supply of air for combustion. Monitoring this pressure difference can help identify issues such as inadequate draft, which could lead to unsafe conditions or inefficient operation. Hence, understanding the draft characteristics is vital for ensuring safe and efficient appliance performance.