A control systems engineer required a high-sensitivity pressure sensor to form the basis of an automated ventilation system for a yacht’s engine room. The system’s goal was to maintain a specific negative air pressure to ensure crew safety by containing fumes, and it required a durable sensor for the demanding marine environment. The PrimAtü 10 series was selected for its ability to meet the precise measurement and operational requirements of the application.
- Application: Automated fan speed control for yacht engine room pressurisation.
- Measurement Goal: Maintain -50 Pa differential pressure.
- Sensor Requirement: Bi-directional measurement from -100 to +100 Pa.
- Key Features: 4-20mA output, local LCD display, IP65-rated enclosure.
A customer developing sophisticated automated control systems for the marine industry required a precise and reliable method for managing the engine room ventilation on a yacht. The primary objective of their fan speed control system was to maintain a slight negative air pressure of -50 Pascals within the engine room relative to the outside atmosphere whenever the main engines were operational. This negative pressure is a critical safety feature on marine vessels; it ensures that air flows from adjacent accommodation areas into the engine room, thereby containing any potentially hazardous fumes or smoke within the machinery space before being safely exhausted overboard.
To achieve this, the control system needed to continuously monitor the pressure difference between the engine room and the exterior. The application demanded a sensor capable of bi-directional measurement with a range of -100 to +100 Pascals. This range would allow the system to precisely regulate the -50 Pa target, while also detecting any unwanted pressure deviations. For example, it could identify if the pressure became too negative (potentially starving the engines of combustion air) or if a fault in the exhaust fans caused the pressure to drift towards a positive value, which would defeat the fume containment. The sensor was to be physically installed on a bulkhead within the engine room—a challenging environment with elevated temperatures, humidity, and vibration. For integration, a robust 4-20mA analog output was required, and for ease of local diagnostics, an integrated digital display was also specified.
The proposed solution was the PrimAtü 10 series low-range differential pressure transmitter. This instrument was perfectly suited to the customer’s demands due to its specialized design for detecting very small variations in air pressure. The core of the device is a piezoresistive silicon sensing element, which provides the high sensitivity needed to reliably measure pressures at the Pascal level. The transmitter was configured with a bi-directional measurement range of -100 to +100 Pa and a corresponding 4-20mA output, where 4mA represents -100 Pa, 12mA represents 0 Pa, and 20mA represents +100 Pa. This provided a clear and standard signal for seamless integration with the fan control system.
Several features of the PrimAtü 10 series made it an ideal choice for this specific marine application. The optional integrated four-digit LCD display satisfied the need for on-site verification of the engine room pressure without requiring external test equipment. Its IP65-rated housing ensures the internal electronics are protected from dust and water spray, guaranteeing durability and long-term reliability within the demanding engine room environment. Furthermore, the transmitter includes simple push-buttons for on-site zero and amplitude (span) adjustment. This is a significant benefit for the commissioning and maintenance engineer, allowing them to periodically check and correct the calibration to ensure the ventilation control system remains accurate and effective throughout its service life.
PrimAtü 10 Low Range Differential Pressure Transmitter
- Pressure Range: -100 to +100 Pa
- Range Type: Differential (-P to +P)
- Output Signal: 4-20mA
- Overall Accuracy: 1% 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