Model DDSM1 draft simulator allows HVAC professionals to accurately test pressure switches and calibrate adjustable pressure switches to any furnace. This allows technicians to carry adjustable switches on their trucks, instead of switches for a variety of furnaces, said the company. Designed to simulate the negative pressure created by the draft inducer at start-up, when used with a manometer, the DDSM1 produces a consistent vacuum pressure that is adjustable to the furnace pressure, and it will maintain that pressure from 0-100 inches of column water, depending on the bleed port. To use the DDSM1, with the furnace turned off, it can be simply connected via the supplied leads and hoses to the pressure switch and a manometer, turn on the draft simulator, and slowly adjust the pressure dial. The red LED indicates when the pressure switch closes. The tech checks the reading on the manometer to see what pressures open and close the switch. According to the company, the amount of pressure to open and close the switch should be within 10 percent of the manufacturer’s rating. In addition to furnaces, the DDSM1 can accurately test pressure switches in boilers, water heaters, filter systems, clean rooms, draft hoods, air balance, and zoning. The DDSM1 can also be used to test signal transducers on furnace boards. The draft simulator features long battery life, sturdy controls, a tilt stand, and a rugged reinforced shell for extra grip and protection from drops.
Fieldpiece Instruments Inc.