When Steve Asselin, a project manager and specialist in automated test measurement, came to Heat Transfer Products Inc., a manufacturer of water tanks and water heating appliances, his initial assignment was to design a production line for the company’s compact, modular Munchkin water heaters.
According to Asselin, the most important aspect of designing the new Munchkin production line would take place during the final stages of assembly. During the testing stage, each boiler would be checked for its ability to literally "perform under pressure."
Asselin called on Setra Systems, Boxborough, MA, a manufacturer of electronic instrumentation for measuring pressure, acceleration and weight, to provide the test measurement devices he needed for the essential testing phase.
Paul Richards, Asselin's contact at Setra, suggested the Model 201 pressure transducer.
Asselin set up two testing lines for the Munchkin boilers. The Setra Model 201 would come into play during the boiler-firing rate test, where the boiler is tested to make sure it is firing at its designed rate. This test ensures that the appliance produces the right amount of heat for its rate designation.
The Model 201 Pressure Transducer features a rugged design, wide operating range (-40F to 175F) and a high 45 psi overpressure capability, so it is well suited for applications such as boiler gas pressure measurement, as well as vapor recovery systems, exhaust gas control systems and industrial scrubbers. Its all-welded, no o-ring construction provides a leak-free design suitable for measuring hazardous gasses, and it's also ideal for measuring very low differential or gauge pressures.
During Heat Transfer’s boiler-firing rate test, water from a 2,400-gallon tank is pumped through the boiler being tested. As the boiler heats up, the gas flow into the boiler as well as other parameters are measured to determine the firing rate of the boiler. In order to accurately determine the gas flow rate, the pressure of the gas flowing into the boiler must be known and the Model 201 is used to measure this pressure.
The Model 201 features an Inconel diaphragm and an insulated electrode, which forms a variable capacitor. As the sensor pressure increases or decreases, the capacitance changes. This change in capacitance is detected and converted to a fully conditioned, easy-to-read linear current output signal.
“We have two shifts of technicians testing boilers,” explained Asselin. “It takes several minutes to fully test each boiler. After each Munchkin is tested, it then proceeds down the assembly line for final inspection and packing."
Asselin had accomplished his mission, establishing a new production line which incorporated an efficient and reliable testing phase. Now that the pressure is off, figuratively speaking, Asselin is already working the Model 201 into future testing projects.