Engineers aboard a large vessel sought a reliable method to monitor and control the air pressure within the sealed engine room to ensure optimal conditions for engine combustion and heat management. The solution involved implementing a highly sensitive differential pressure sensor to provide real-time data to the ventilation control system. This maintained a precise, slight negative pressure, preventing engine air starvation and ensuring efficient operation.
- Application: Marine Engine Room Air Pressure Balancing
- Challenge: Preventing engine combustion air starvation while managing heat extraction through ventilation.
- Measurement: Low-range bidirectional differential pressure from -100 to +100 Pascals.
- Solution: A low-range differential pressure sensor with an analogue output for fan speed control and a local display.
A critical operational requirement for engineers on large vessels is the precise management of air pressure within the sealed engine room. This space houses the main propulsion engines and generators, which consume vast quantities of air for combustion. Simultaneously, powerful ventilation systems run continuously to extract excess heat. This interplay creates a complex pressure environment where imbalances can lead to significant problems. The primary challenge is to maintain a specific, slight negative pressure relative to adjoining areas of the vessel. If the pressure drops too low, creating a partial vacuum, the engines can be starved of combustion air, resulting in poor fuel efficiency, increased emissions, and potentially reduced power output. The engineering team required a monitoring solution to provide real-time data for adjusting ventilation fan speeds to maintain this delicate balance.
The specific application required a sensor capable of accurately measuring very low-level bidirectional pressures, meaning it had to monitor both positive pressure and negative pressure (vacuum). The required measurement range was determined to be approximately -100 to +100 Pascals (-1 to +1 mbar), relative to the air pressure immediately outside the engine room. To be effective, the instrument needed to provide a stable, continuous analogue output signal that could be fed into the vessel’s fan control system, allowing for automated or precise manual adjustments. Furthermore, given the nature of a marine engine room, a robust enclosure with protection against moisture and dust, along with an optional local display for at-a-glance readings by the crew, were highly desirable features.
The PrimAtü 10 series low-range differential pressure sensor was identified as the ideal instrument for this task. Its core technology, a piezoresistive silicon sensor, is specifically designed for the high sensitivity needed to resolve pressure changes at such low levels. A key advantage of the PrimAtü 10 is its availability in a bidirectional configuration, allowing it to be factory set to the exact -100 to +100 Pa range required for this engine room pressure balancing application.
The sensor provides selectable analogue outputs, such as 0-10 V or 4-20 mA, enabling seamless integration with the existing ventilation fan controllers. The solution included the optional integrated 4-digit LCD display, giving engineers and technicians instant visual confirmation of the live pressure differential without needing to check a central control panel. Critically for a marine installation, the unit is housed in an IP65-rated enclosure, which ensures the internal electronics are protected from dust and water spray. An additional feature beneficial for long-term reliability is the inclusion of push buttons for on-site zero and span adjustment, allowing the vessel’s technicians to perform periodic calibration checks easily, ensuring sustained accuracy over the life of the installation.
PrimAtü 10 Low Range Differential Pressure Sensor
- Pressure Range: -100 to +100 Pa (-1 to +1mbar)
- Range Type: Bi-Directional Differential (-P to +P)
- Output Signal: Selectable – 0/4-20mA or 0-10V dc
- Overall Accuracy: 2% FS
- Electrical Connection: Cable glands with internal screw terminals
- Process Connection: 6.6mm dia x 10mm barbed connections
- Media Compatibility: Non aggressive gases compatible with Ni, Al, CuBe, PU, silicon rubber
- Optional Extras: Integrated LC-display, 4 digit