Blackbody calibration sources manufactured by Nagman enable accurate calibration of infrared temperature sensors with minimal measurement error. These devices provide a stable and controlled temperature reference, ensuring reliable performance in industrial and laboratory environments.
This article explains what a blackbody calibration source is, its working principle, types available, and how it differs from other infrared temperature calibration devices.
What is a Blackbody Calibration Source?
A blackbody calibration source is an instrument used to verify and calibrate infrared temperature sensors and pyrometers. It provides a precisely controlled heated (or cooled) target with a known temperature, allowing accurate comparison and adjustment of infrared measuring instruments.
A blackbody is considered a perfect radiator, meaning it absorbs and emits thermal radiation efficiently. According to Planck’s Law of Radiation, the emitted energy depends only on temperature and wavelength. In theory, a perfect blackbody has an emissivity of 1.
In practice, real calibration sources achieve emissivity values very close to 1 (typically 0.95 to 0.98 or higher), through advanced engineering and design.
For accurate calibration:
The sensor’s emissivity setting must match the source
The sensor must be positioned properly
The measurement spot size should be smaller than the aperture diameter
These factors ensure reliable and repeatable calibration results.
Types of Blackbody Calibration Sources
Blackbody sources are mainly classified into two types:
1. Hot Plate-Type Blackbody Source
Hot plate-type sources consist of a temperature-controlled metal plate. The surface is typically coated with high-emissivity black paint to improve radiation characteristics.
Features:
Simple construction
Emissivity up to 0.95
Suitable for general-purpose infrared calibration
Controlled by thermostat or advanced temperature controller
This type is often used in routine industrial applications.
2. Cavity-Type Blackbody Source
Cavity-type blackbody sources provide higher accuracy and better emissivity performance. They consist of a heated cavity with a small aperture.
When radiation enters the cavity:
It reflects multiple times
Gets absorbed and thermalized
Only temperature-dependent radiation exits
Because of this design, cavity-type sources can achieve emissivity values of 0.98 or higher.
They are commonly used in:
Calibration laboratories
Reference-level radiation thermometry
High-precision industrial testing
Difference Between Blackbody Calibrator and Flat-type IR Temperature Calibrator
When selecting an infrared temperature calibration device, the design of the target surface is an important factor.
Blackbody Calibrator:
Uses a cavity with a small aperture
High emissivity (close to 1)
Superior radiation uniformity
Used for reference-grade calibration
Flat-Plate IR Temperature Calibrator:
Uses a painted flat target surface
May include ridges or textured designs
Generally lower emissivity compared to cavity type
Surface uniformity may vary
While flat-type calibrators are suitable for general applications, cavity-type blackbody calibrators offer better accuracy and consistency for critical calibration tasks.
Key Factors to Consider When Selecting a Blackbody Calibration Source
To choose the ideal solution for your application, consider:
Required temperature range
Emissivity performance
Aperture size
Surface uniformity
Temperature stability
Calibration frequency
Industrial or laboratory usage
Selecting the right model ensures long-term reliability and measurement accuracy.
Why Choose Nagman Blackbody Calibration Sources?
Nagman is a trusted manufacturer of high-emissivity blackbody radiation sources designed for precision and stability. With advanced temperature control systems and uniform surface performance, Nagman solutions support accurate and repeatable infrared sensor calibration.
Nagman offers:
High emissivity cavity designs
Stable and uniform temperature control
Multiple aperture diameter options
Flexible sensor integration
Reliable performance for periodic calibration
Conclusion
A blackbody calibration source is an essential instrument for accurate infrared temperature calibration. Whether used in industrial environments or laboratory settings, it ensures reliable temperature reference and improved measurement precision.
By selecting the appropriate type and specifications, industries can maintain calibration accuracy and ensure dependable thermal measurement performance.
