Sensors

Sensor Selection & Optimization

Koftech brings a systems-approach for product development where the interactions between different components and subsystems is key to a successful product. We prefer to integrate with our clients’ design teams at early concept design stages and bring the expertise in selecting and validating optimal sensors for the application at hand. Our expertise spans sensors ranging from visible light to x-rays. For a given application, we analyze a number of sensor properties to select and optimize system performance.
Wavelength To detect x-rays, the typical approach involves converting some of the incident x-rays energies to light via interaction with a scintillating material and then detect the produced light photons. Each scintillating material produces light peaked at a wavelength specific to it. Selecting a photo-detector (e.g., photo-multiplier) involves analyzing its response to match it to the wavelength produced by the scintillator.
Interaction Cross-Section In x-ray and other high-energy modalities, scintillator material that converts some of the incident energy into light has an inherent interaction cross-section, which determines the probability of interaction over a unit of volume as a function of incident energy. Cross-section analysis is a prerequisite for selecting optimal scintillator material and thickness.
Linearity of Response A sensor with linear response means that its output is a linear function of its input. Linear response is desired to avoid related imaging artifacts especially in applications with sensor arrays (e.g., flat-panel detector arrays), each with its characteristic non-linear response curve.
Dark Current Each sensor has some level of dark current. As the name implies, it refers to the current (signal) produced by the sensor in absence of input (dark). Dark-current is a form of signal independent noise process with a non-zero mean. Dark-current noise tend to be white (flat frequency response) making it harder to filter it out. Hence, when selecting a sensor, it’s important to analyze its dark-current levels (mean and standard deviation) and ensure they’re small relative to sensor’s dynamic range. Poor dark-current optimization reduces the system’s overall signal to noise ratio.
Dynamic Range Dynamic range is related to a sensor’s sensitivity to input signal and reflects the range of input signal levels it can detect and discern. When selecting a sensor for a given application, it’s very important to consider the sensor’s dynamic range and make sure it is wide enough capture incoming signals. Sensors are often designed to operate through a wide range of applications with varying dynamic range requirements. Hence, sensor vendors equip sensors with the means to optimize the sensor performance for a specific application. This includes optimizing sensor gain, offset, integration time, and filtration.
Operational Environment A sensor’s response may depend on environmental parameters such as temperature, humidity, and pressure. Hence, it’s very important to analyze the operational environment and how corresponding sensor response. A sensor is typically installed as part of a system containing other sensors, power supplies, motors, and more. It’s important to understand the interactions between this sensor and others in the system to minimize cross-talk and interference.

Koftech brings a systems-approach for product development where the interactions between different components and subsystems is key to a successful product. We prefer to integrate with our clients’ design teams at early concept design stages and bring the expertise in selecting and validating optimal sensors for the application at hand.

Our expertise spans sensors ranging from visible light to x-rays. For a given application, we analyze a number of sensor properties to select and optimize system performance.

Wavelength

To detect x-rays, the typical approach involves converting some of the incident x-rays energies to light via interaction with a scintillating material and then detect the produced light photons. Each scintillating material produces light peaked at a wavelength specific to it. Selecting a photo-detector (e.g., photo-multiplier) involves analyzing its response to match it to the wavelength produced by the scintillator.

Interaction Cross-Section

In x-ray and other high-energy modalities, scintillator material that converts some of the incident energy into light has an inherent interaction cross-section, which determines the probability of interaction over a unit of volume as a function of incident energy. Cross-section analysis is a prerequisite for selecting optimal scintillator material and thickness.

Linearity of Response

A sensor with linear response means that its output is a linear function of its input. Linear response is desired to avoid related imaging artifacts especially in applications with sensor arrays (e.g., flat-panel detector arrays), each with its characteristic non-linear response curve.

Dark Current

Each sensor has some level of dark current. As the name implies, it refers to the current (signal) produced by the sensor in absence of input (dark). Dark-current is a form of signal independent noise process with a non-zero mean. Dark-current noise tend to be white (flat frequency response) making it harder to filter it out. Hence, when selecting a sensor, it’s important to analyze its dark-current levels (mean and standard deviation) and ensure they’re small relative to sensor’s dynamic range. Poor dark-current optimization reduces the system’s overall signal to noise ratio.

Dynamic Range

Dynamic range is related to a sensor’s sensitivity to input signal and reflects the range of input signal levels it can detect and discern. When selecting a sensor for a given application, it’s very important to consider the sensor’s dynamic range and make sure it is wide enough capture incoming signals.

Sensors are often designed to operate through a wide range of applications with varying dynamic range requirements. Hence, sensor vendors equip sensors with the means to optimize the sensor performance for a specific application. This includes optimizing sensor gain, offset, integration time, and filtration.

Operational Environment

A sensor’s response may depend on environmental parameters such as temperature, humidity, and pressure. Hence, it’s very important to analyze the operational environment and how corresponding sensor response.

A sensor is typically installed as part of a system containing other sensors, power supplies, motors, and more. It’s important to understand the interactions between this sensor and others in the system to minimize cross-talk and interference.