CE311 444-311-000-012 Piezoelectric Accelerometer

The CE311 444‑311‑000‑012 is a high‑performance piezoelectric accelerometer with integrated electronics from Meggitt’s renowned vibro‑meter® product line, specifically engineered for industrial vibration monitoring where robust, long‑term reliability and simplified installation are essential. This standard, non‑Ex version features a sensitivity of 50 μA/g and is supplied with a factory‑fitted 3‑metre integral cable, protected by a flexible, leak‑tight stainless‑steel hose. This ready‑to‑install configuration eliminates the need for a separate connector at the sensor end, providing a continuous, hermetically sealed connection that is ideal for permanent installations in harsh environments where protection against cooling fluids, lubricants, water, steam, and other contaminants is critical. The sensor delivers a current‑modulated output signal proportional to acceleration, with a frequency response from 2 Hz to 8 kHz, making it suitable for a wide range of rotating and reciprocating machinery, from slow‑speed pumps to high‑speed gearboxes and turbines.

The CE311 444‑311‑000‑012 is an industry‑standard current‑output IEPE‑type sensor that requires a constant current power supply (5 to 8 mA) and operates from a 15 to 28 VDC supply. It provides a low‑impedance current‑modulated output that is largely insensitive to cable capacitance and electromagnetic interference, permitting long‑distance signal transmission without degradation. The integrated electronics incorporate internal shielding and are galvanically isolated from the sensor case, ensuring exceptional noise immunity, reduced ground‑loop interference, and stable bias‑voltage performance.

The sensor is housed in a hermetically sealed stainless‑steel case (1.4441) with the integral cable protected by a stainless‑steel hose (1.4541). The sensor and protection tube are hermetically welded to one another, creating a leak‑tight assembly that is impervious to 100 % relative humidity, water, steam, oil, sea‑salt atmospheres, dust, fungus, and sand. This rugged construction ensures decades of reliable operation in the harshest industrial environments, including offshore, chemical, and outdoor installations.

With a frequency response of –3 dB at 2 Hz, ≤±5 % from 6 Hz to 5 kHz, and ≤±10 % from 5 kHz to 8 kHz, a nominal resonant frequency of 20 kHz, and a dynamic range of 0.004 g to 40 g peak, the CE311 444‑311‑000‑012 captures low‑frequency structural vibrations and high‑frequency gearmesh signatures with good fidelity. Its temperature range of –40 °C to 125 °C, combined with excellent temperature stability (±5 % over the full range), ensures reliable operation in a wide variety of industrial process environments. The sensor’s low noise and outstanding electromagnetic immunity make it ideal for precision condition monitoring and predictive maintenance programmes.

This product introduction provides a comprehensive description of the CE311 444‑311‑000‑012, including key features, applications, detailed technical specifications in tabular form, installation guidelines, ordering information, and available accessories. All information is derived from the official Meggitt data sheet (CE311 old version) and reflects the company’s commitment to engineering excellence and customer support.

Key Features and Benefits

Integral Cable with Stainless‑Steel Protection Tube – 3 Metre Length – The factory‑fitted 3‑metre cable (twisted‑pair shielded) with a flexible, leak‑tight stainless‑steel hose provides exceptional mechanical protection, chemical resistance, and durability. The sealed, connector‑less design eliminates potential failure points at the sensor interface, ensuring long‑term signal integrity in harsh environments. The 3‑metre length is ideal for many installations where the sensor is mounted close to the monitoring electronics, such as on compressors, pumps, or small turbines.

High Sensitivity and Wide Dynamic Range – With a sensitivity of 50 μA/g ±5 % and a dynamic range from 0.004 g to 40 g peak, the sensor captures a broad spectrum of vibration amplitudes, from subtle bearing wear to moderate imbalance events, without saturation.

Extended Frequency Response – The sensor offers a –3 dB point at 2 Hz, a flat response of ±5 % from 6 Hz to 5 kHz, and ±10 % from 5 kHz to 8 kHz, covering low‑frequency structural motions and high‑frequency gearmesh and blade‑pass frequencies.

Low Noise and High Resolution – The residual electrical noise is very low, ensuring clear detection of low‑level vibrations. The internal shielding and isolated electronics further suppress electromagnetic interference.

Integrated Electronics (IEPE) – The built‑in charge‑to‑current converter eliminates the need for an external charge amplifier. The 2‑wire interface carries both power and signal, simplifying cabling and reducing system cost. The sensor operates with a constant current of 5 to 8 mA and a supply voltage of 15 to 28 VDC.

Ground‑Isolated Case with Internal Shield – The sensor case is electrically isolated from the signal ground, with a minimum isolation resistance, preventing ground loops. An internal shield further enhances noise rejection, ensuring clean signal transmission even when mounted on grounded metal structures.

Rugged Hermetically Welded Construction – The hermetically welded stainless‑steel housing and protection tube provide IP protection against dust, water, and a wide range of industrial contaminants. The leak‑tight assembly is impervious to 100 % relative humidity, water, steam, oil, sea‑salt, dust, fungus, and sand, ensuring long‑term reliability.

Wide Operating Temperature Range – The CE311 444‑311‑000‑012 operates continuously from –40 °C to 125 °C, with a temperature sensitivity deviation of ±5 % over the full range, making it suitable for applications ranging from cold outdoor environments to hot process areas.

High Shock Tolerance – With a shock limit of 500 g peak (half‑sine, 1 ms), the sensor withstands severe mechanical transients without damage, ensuring survivability in demanding machinery environments.

Low Base Strain Sensitivity – The base strain sensitivity is only 0.0015 g/με typical, minimising measurement errors caused by mounting surface deformation.

Easy Installation – The integral cable is terminated with flying leads (colour‑coded), allowing direct connection to terminal blocks or junction boxes. The sensor is mounted using four M6 bolts with a recommended torque of 15 N·m, providing secure attachment.

Factory Calibration – Each unit is dynamically calibrated at the factory at 120 Hz and 5 g peak; no subsequent calibration is required under normal use, reducing maintenance costs.

CE Marked, EAC, and RoHS Compliant – The sensor meets European Union EMC, electrical safety, and RoHS requirements, as well as Eurasian Customs Union standards, ensuring global acceptance.

Applications

The CE311 444‑311‑000‑012 is ideally suited for a wide range of industrial vibration monitoring applications in non‑hazardous areas, including:

• Pumps and Compressors – Continuous monitoring of centrifugal, reciprocating, and axial machines for imbalance, cavitation, bearing wear, and surge detection.

• Fans and Blowers – Condition monitoring of HVAC systems, cooling towers, and process ventilation fans.

• Motors and Generators – Vibration analysis of electric motors, diesel generators, and turbine‑generator sets to detect rotor unbalance, misalignment, and bearing defects.

• Gearboxes and Gear Drives – High‑frequency measurement for gearmesh and bearing fault detection in industrial gearboxes.

• Turbines (Gas, Steam, Hydro) – Monitoring of bearing housing and casing vibration in power generation and mechanical drive applications.

• Machine Tools and Spindles – Vibration monitoring of high‑speed spindles and CNC equipment for predictive maintenance.

• Test and Measurement – Permanent or temporary installations for performance validation, modal analysis, and troubleshooting.

• Paper, Steel, and Cement Mills – Harsh environment monitoring of rollers, crushers, conveyors, and continuous casting machinery.

• Marine and Offshore – Vibration measurement on propulsion systems, deck machinery, and auxiliary equipment.

• General Industrial Condition Monitoring – Any rotating or reciprocating machinery in factories, power plants, and processing facilities requiring reliable, cost‑effective vibration data.

Detailed Description of the Standard Version (444‑311‑000‑012)

The CE311 444‑311‑000‑012 is the standard, non‑Ex variant of the CE311 family, featuring a sensitivity of 50 μA/g and a temperature range of –40 °C to 125 °C. It is supplied with a 3‑metre integral cable protected by a flexible stainless‑steel hose, terminated with flying leads for direct connection. It is designed for permanent installation in ordinary industrial environments where a robust, sealed, connector‑less solution is required to maximise reliability and minimise installation complexity.

The sensor is built around a symmetrical shear‑mode piezoelectric measuring element using polycrystalline material. The integrated electronics package, housed within the sensor casing, converts the charge generated by the piezoelectric element into a proportional current signal. The current‑modulated output (2‑wire system) carries both power to the sensor and the signal from the sensor over the same two conductors. Because the output is a current signal, it is largely insensitive to cable capacitance and electromagnetic interference, permitting cable runs of several hundred metres without signal attenuation or degradation. This makes the CE311 particularly well‑suited for installations where the sensor is located far from the monitoring electronics.

The ground‑isolated design ensures that the sensor case and mounting base are electrically isolated from the signal ground, preventing ground loops. The internal shielding and isolated electronics further attenuate electromagnetic interference, ensuring clean signal transmission even in environments with strong electrical fields.

The mechanical construction features a hermetically welded stainless‑steel housing (1.4441) that provides robust protection. The integral cable is welded to the sensor at the factory, creating a continuous, leak‑tight seal that prevents moisture ingress and ensures long‑term reliability. The cable is a twisted‑pair shielded cable, and the flexible stainless‑steel hose (1.4541) offers robust protection against abrasion, cutting, and chemical attack. The cable is terminated with flying leads (colour‑coded) allowing direct wiring to terminal blocks or junction boxes, eliminating the need for an intermediate connector that could be a potential failure point.

The mounting interface consists of four M6×35 Allen bolts (12.9 steel) with four M6 spring‑steel washers. The recommended mounting torque is 15 N·m (11.1 lb‑ft), ensuring proper coupling and optimal high‑frequency response. The sensor is designed to be mounted on flat, clean surfaces to achieve the specified frequency response and sensitivity.

The CE311 444‑311‑000‑012 is factory‑calibrated at 120 Hz and 5 g peak at 23 °C, with the sensitivity verified to be within ±5 % of the nominal 50 μA/g. No subsequent calibration is required under normal use, but periodic verification (e.g., every 2‑5 years) is recommended for critical applications.

This standard version (non‑Ex) is not certified for use in hazardous areas. For such applications, Ex‑certified versions (e.g., 444‑311‑000‑112 with 3 m cable) are available, featuring intrinsic safety (Ex ia) or non‑sparking (Ex nA) protection.

Installation and Mounting Guidelines

Proper installation is essential to achieve the specified performance from the CE311 444‑311‑000‑012. The following guidelines are based on Meggitt’s recommended practices:

• Mounting Surface Preparation – The mounting surface should be flat, smooth, and clean. Any burrs, paint, or corrosion must be removed to ensure full contact between the sensor base and the machine surface. A surface finish of 1.6 µm (63 µin) or better is recommended for optimal high‑frequency response.

• Bolts and Washers – Use the supplied M6×35 Allen bolts (12.9 steel) and M6 spring‑steel washers (DIN 7980). Apply the recommended torque of 15 N·m (11.1 lb‑ft) evenly across all four bolts. Do not over‑torque, as this may damage the threads or the sensor housing.

• Orientation and Alignment – The sensor is sensitive along its principal axis (marked on the housing). Align the sensor such that the principal axis coincides with the direction of the vibration to be measured (axial, radial, or tangential). Refer to the installation manual for detailed orientation diagrams.

• Cable Routing and Termination – The integral cable is protected by a flexible stainless‑steel hose. Route the cable with a minimum bend radius to avoid stress and internal damage (recommended > 50 mm). Secure the cable at intervals using P‑clips or cable ties, but avoid over‑tightening that could deform the hose. The flying leads are colour‑coded; connect them to the monitoring system’s constant current supply and signal input according to the wiring diagram. The cable shield should be grounded at one end (typically at the monitoring system) to minimise electromagnetic interference.

• Electrical Connections – The sensor requires a constant current power supply of 5 to 8 mA and a supply voltage of 15 to 28 VDC. The signal is measured as the AC current component on the bias level. Ensure the monitoring system provides the appropriate signal conditioning (e.g., current‑to‑voltage conversion and high‑pass filtering). The cable shield should be grounded at one end.

• Grounding – The sensor’s base is isolated from the signal ground, so the mounting surface can be at any potential without affecting the signal. However, the cable shield should be grounded at one end to minimise electromagnetic interference. Follow the grounding practices recommended in the system’s installation manual.

• Thermal Considerations – The sensor is rated for continuous operation up to 125 °C. If the mounting surface exceeds this temperature, use a thermal insulating adaptor (e.g., MA133) or mount the sensor remotely with an extension rod. Ensure that the cable hose is not routed over hot surfaces that exceed its material limits.

• Protection from Physical Damage – In harsh environments, protect the sensor and cable from impacts, abrasion, and chemical attack. The stainless‑steel hose provides substantial protection, but additional conduits or protective covers may be required in extreme conditions.

• Hazardous Area Precautions – This standard version is not Ex‑certified; therefore, it must not be used in potentially explosive atmospheres. For such areas, use the Ex‑certified versions (e.g., 444‑311‑000‑112) and follow the specific installation requirements of the Ex certificates.

Commissioning and Verification

After installation, the CE311 444‑311‑000‑012 should be verified using a known vibration source (e.g., a portable shaker or a reference accelerometer) or by comparing with a known good sensor. The bias current should be measured to confirm it is within the specified 5 to 8 mA range. The AC signal should be checked for proper sensitivity; a known acceleration level (e.g., 1 g at 80 Hz) should produce the expected output current change (50 μA/g). Also verify that the signal is free from excessive noise and that the low‑frequency cutoff is appropriate for the intended measurement. For long‑term monitoring, regular system checks during routine maintenance are recommended.

Ordering Information

The CE311 444‑311‑000‑012 is ordered using the following designation:

Note: Other cable lengths may be available upon request. Ex versions feature intrinsic safety (Ex ia) or non‑sparking (Ex nA) certification.

Accessories

A range of accessories is available to complement the CE311 444‑311‑000‑012, including mounting adaptors, connectors, junction boxes, and galvanic separation units.

Note: For Ex installations, use only certified connectors, cables, and barriers as specified in the relevant Ex certificates.

Disposal and Environmental Compliance

At the end of its service life, the CE311 444‑311‑000‑012 must be disposed of in accordance with local environmental regulations. The sensor contains stainless steel, electronic components, and piezoelectric materials; the cable contains metal conductors and insulation. In the European Union, the Waste Electrical and Electronic Equipment (WEEE) Directive applies – separate collection and recycling are mandatory. Meggitt supports environmentally responsible disposal and can provide guidance on proper recycling channels.