JSA ENGINEERING & SERVICES–JSA ENGINEERING & SERVICES

Unlike standard transmitters that use a flat diaphragm, these utilize a capsule made of two corrugated metal diaphragms welded together.

The Mechanism: When pressure is applied to the interior of the capsule, it expands. Because the surface area is effectively doubled (compared to a single diaphragm), the capsule provides a much larger mechanical displacement for a given amount of pressure.
Signal Conversion: This mechanical movement is typically converted into an electrical signal using an LVDT (Linear Variable Differential Transformer) or a capacitive sensor, then processed into a standard 4-20 mA or digital output (HART/Foundation Fieldbus).
High Sensitivity: Specifically engineered for Low Draft and Low Pressure measurements that would be "noise" to a standard heavy-duty sensor.
Accuracy: They maintain high linearity even at the bottom of their calibrated scale.
Adjustability: Most modern units offer high "turndown ratios," allowing you to narrow the measurement span significantly without losing precision.

Industry	Application
HVAC / Cleanrooms	Monitoring room static pressure and filter blockage.
Power & Utilities	Measuring furnace draft pressure and flue gas flow.
Medical / Lab	Precise monitoring of vacuum or low-pressure gas lines.
Industrial Boilers	Air-to-fuel ratio control and combustion air pressure.