Sensor Selection Guide

Selecting the Right Sensor for Your Application

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Jewell Instruments manufactures high precision inertial sensors that incorporate Force Balance, MEMS or Electrolytic sensor technology. How to select the right sensor technology for a specific application generally depends on several factors.

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WHICH SENSOR TECHNOLOGY IS BEST?

Selecting the right sensor technology might be seem like a daunting task, but below is a detailed guide to help you select the best solution for your project:

High Performance motion & tilt sensors are utilized in many industries, even those considered to have harsh environments. In the Military & Aerospace sectors, the use of High precision accelerometers and inclinometers has been widespread for critical navigation, flight control or stabilization functions for decades. The rise of inertial systems used in industrial applications during the last years is driven by the possibility of integrating new functionality at low-cost and good performance, mostly thanks to the recent developments in MEMS sensor technology. To name a few, Bridge Monitoring, Structural Monitoring, Rail Transportation, and a wide range of other Industrial markets including Solar & Wind, Oil & Gas, and Mining are all benefiting from the performance improvements and even cost reductions from new technologies and advancements in integrated circuits.

NARROWING DOWN TO THE RIGHT TECHNOLOGY

For Inertial applications, Force Balance Sensors are generally more accurate, offer higher resolution, can be fluid-damped for applications with high shock and vibration, and are extremely rugged devices.  Inertial sensors with MEMS-based technology tend to be less expensive, but while still can offer high performance, do not typically offer the same level as force balance. Jewell Instruments offers Accelerometers and Inclinometers. For static applications, Electrolytic sensors can offer high-to-Ultra precision capabilities to even 1 nanoradian resolution, but are generally used on Geophysical and Geotechnical applications above or below ground or underwater installations with no shock or vibration during measurements.

For a detailed explanation of each technology, please review the following technical notes:

• How does a Force-Balance Sensor Work?
• How does a MEMS Sensor Work?
• How does an Electrolytic Sensor Work?

Both of our Force-balance & MEMS technology have accelerometer and inclinometer options available. How are they different?

Accelerometer:

a = (Vf – Vi)/t

where Vf is the final velocity, Vi, the initial velocity, and t is time.  A decrease in velocity, where Vf is smaller than Vi, is a negative acceleration, also referred to as deceleration.  The acceleration unit g is equal to the local gravitational field, which is equivalent to free-fall acceleration.  An Angular Accelerometer is a device that senses angular (rotational) acceleration about its input axis and provides an output from moment of inertia acting on a proof-mass, which is proportional to the angular acceleration input. The input is typically in units of radians per second squared (rad/sec²).

At Jewell Instruments, we design and manufacture high precision accelerometers to measure acceleration, vibration, shock, and motion in various applications. These accelerometers are driven by MEMS and force balance technology, making them ideal for a wide range of industrial, commercial, and sensing requirements. Jewell precision accelerometers are offered in single-axis, dual-axis, and tri-axis configurations.

Jewell accelerometers utilize closed-loop sensor technology to produce an accurate output with high resolution. The inertial sensor output is an analog voltage, current, or digital signal proportional to applied acceleration and tilt from DC through a specified frequency. Jewell has produced inertial sensor torquers and complete acceleration sensing assemblies for decades. Jewell inertial sensors are used throughout the world for detecting acceleration up to ±40G. An inertial sensor responds to both earth’s gravity and acceleration.

• Force Balance Accelerometers: These are low noise and high sensitivity sensors, which are designed for various structural and seismic applications. Our force balance accelerometers are distinguished by ruggedness, high reliability, low-profile design, and high precision. These accelerometers find great applications in aerospace, military, rail, industrial, oil & gas and others.

• MEMS Accelerometers: Many Microelectromechanical systems (MEMS) accelerometers are offered with robust enclosures and available in single, dual, and tri-axis models. These precision accelerometers are designed for high stability and low power applications.

Some important parameters to consider before choosing an accelerometer:

• Linear or Angular Acceleration: Is the motion occurring in any particular axis? Or is it a rotational change in velocity about its input axis?
• Number of Axes being measured (1, 2, or 3)
• Vibration levels (Hz): This happens when an object oscillates about its position. Vibration is a common occurrence in automotive and machining environments. Knowing the expected level of vibration during measurements (frequency & amplitude) is an important factor in determining the best solution.
• Minimum Frequency Response (Hz): how fast does the sensor need to respond to changes in input
• Maximum measuring range (g): Highest acceleration expected to be measured by the sensor.
• Shock: A body resonates when there is a sudden excitation of the structure. Important factor for sensor survivability and choosing best accelerometer that can filter out or dampen its effects to output signal
• Output signal*: Our accelerometers are available in analog (±5V, 0-5V, 0.5-4.5V or 4-20mA) and digital signals (ASCII RS232, ASCII RS485, Modbus RS485, or TTL) depending on the model.
• Environmental conditions: The operational environment of the accelerometer needs to be considered. This may involve several parameters, including humidity levels and temperature range.
• Resolution: Jewell offers low-cost options from 0. 5mili-g up to high-precision performance sensors with even 1 micro-g resolution

If you have any questions, a knowledgeable sales team at the manufacturer’s end will help you choose the right accelerometer sensor based on your needs. Being at the forefront of high quality and high precision technologies and products, we understand the precision that various industries demand. We have obtained extensive application knowledge over the years. This allows us to build custom high precision accelerometers for specific applications.

Inclinometer:

Inclinometer is an effective sensor used for a wide range of applications across many industries worldwide. Construction workers use inclinometers to check if the ground is level or slope relative to the horizontal plane. They are also used in surveying to measure the slope of land relative to sea level. Other than this, inclinometers can also be used in scientific experiments and geological research. Additionally, precision tilt sensors are an essential tool for many industries including meteorology, hydropower plant, nuclear power plant, water conservancy project, among others that rely on accurate incline measurements.

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Note that an accelerometer and an inclinometer are the same device. The distinction is one of application, not operation. Accelerometer users typically sense changes in velocity and characterize outputs and errors in g. Inclinometer users sense changes in angular position and think of outputs and errors in units of angular measurement. An inertial instrument responds to both earth’s gravity and acceleration. The inclinometer output is sensing the angle with the respect to the gravity vector. The output follows the relationship of g x sin Ꙩ, where g is acceleration of gravity; sin is trigonometric sine function, Ꙩ is reference angle with respect to the gravity vector. The output can be converted to degrees by the arcsine function.

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A few more application examples include Robot vertical referencing, Auto manufacturing suspension install, Dam sluice gate control, Antenna leveling, Weapons platforms, Missile launchers, Geophysical low range tilt sensing, Platform orientation, Ship and barge leveling, Deviation surveys, Continuous casting for steel industry, Weapons platform leveling, Aircraft flight control, Crane overturning-moment alarms, Electronic level applications.

Jewell high precision inclinometers are used to accurately measure the angle, slope, or tilt of objects in various applications. This measurement is made relative to the gravity of the object. We provide single and dual MEMS and Force-balance inclinometers with analog or digital output signals to meet clients’ measurement requirements. In addition to this, we provide these precision inclinometers sensors in different signal ranges, packages, and are suited for harsh environmental conditions. Inclinometer sensors from Jewell Instruments are widely used for surface measurements in utilities, oil and gas, and construction industries due to their unique features:

• Our Force-Balanced Inclinometers are a type of inclinometer sensor that use a balanced lever system to provide measurements of horizontal angle or vertical deviation with very high resolution.
• With rugged enclosures, high temperature, and vibration resistance, our range of forced balance inclinometers filter shock and vibration from readings.
• They are suitable for applications where high levels of shock and vibration are present.
• Many models are available with a pin terminal, M12 connector, DB9, and other termination options.
• Numerous products are equipped with voltage, current, or digital output to meet our customers’ requirements.
• They are equipped with high accuracy closed-loop force balanced sensor technology.
• Our MEMS inclinometers are low-cost, high-performance sensors in small packages.
• The models under this category can measure inclination from +/-1° to +/-90°
• They are available with custom ranges and output types.
• MEMS inclinometers are available in single-axis and dual-axis configurations.

Some important parameters to consider before choosing an inclinometer:

Jewell Instruments offers a wide range of high precision inclinometers to meet the rising demand from varied industrial applications. The following will provide some important factors to consider when choosing the best inclinometer sensor for your project:

*Note:

The required cable length can also be an important factor in determining the best sensor since:

• Analog output is typically used for applications that do not require long cable lengths since voltage is susceptible to noise interference from vibration and RF waves. A thicker, shielded cable can be used to resist noise and allow cable lengths to run to 50 feet or more. This comes in handy for industrial manufacturing applications where longer cables are needed, but there is a lot of outside movement and vibration.
• Current output is more immune to outside interference which means it can run through cable lengths of 4,000+ meters. For really long lengths, a shielded cable may be necessary to resist outside noise and vibration. This is used for putting a sensor in hard-to-reach places such as structural monitoring, retaining walls, slope stability, volcano studies, and platform leveling and positioning.
• Digital output can provide a variance of cable lengths based on which signal is used. The maximum length for RS-232 output is 15 meters, which is fine for industrial automation and testing. RS-422 and RS-485 are capable of up to 1,000 meters of cable distance giving you more ability for things like structural monitoring.

If you are looking for a leading inclinometer sensor manufacturer and supplier, we are your best choice. With several years of experience in the market, we are committed to offer you the industry best precision inclinometers that stand the test of the time. Once a technology is selected for a high precision accelerometer or inclinometer, exactly what specific model sensor depends on a range of factors for a given application.