How does NIR work

Near Infrared (NIR) spectroscopy uses light transmission and absorption to measure various constituents in a sample material, including moisture, starch, protein, fat and oils. NIR can be used to detect these specific elements, understand the concentration of the elements and detect changes in the overall composition. Because NIR penetrates deeper into bulk material than mid-infrared, it provides better, more reliable measurement on a production line.

NIR works by shining broad-spectrum light on a material, typically from 780nm to 2500nm. The wavelengths that are illuminated on the material are measured by examining the ratio between 2 frequencies — one reference and one at the resonant frequency. From these two measurements, calculations are made that provide data based on the absorption and scattering of the wavelengths caused by the sample.

Readiness and Reliability

In a typical installation, the NIR sensor is mounted over a conveying system (belt, screw, vibratory or pneumatic) about 7-15 inches above the product to be measured. The sensor shines light onto the surface of the product, and after the light hits the product, the calculations to measure the necessary constituents are done. Filters and cell detectors tailored and optimized for your specific application needs are used to zero in on the exact constituent being measured to provide the best results possible.

The readiness and reliability of this data help you minimize product loss, eliminate the need for unnecessary downtime and increase your operation’s efficiency. This results in better margins and increased profits.

Why Use Near Infrared (NIR)

The near infrared (NIR) region, which is invisible to the naked eye, was first detected in the 1800s and gained acceptance in the early 1900s, but was discarded as too broad and too weak to provide specific analytical functions. It wasn’t until the 1990s that research into NIR led to the discovery of its importance in measuring important constituents in food production, building materials, paper manufacturing, pharmaceuticals and biomass, among many other industries.

NIR can detect trace amounts of water, proteins, sugar, oil/fats, nicotine, and resin quickly and without damaging or contacting the sample. It also penetrates deeper into material than other techniques. This combination gives NIR a distinct advantage, saving time and money at many points along the manufacturing line.

NIR is capable of estimating the concentration of the following common properties:

• Protein
• Humidity/water
• Hydrocarbons
• Carboxylic acids
• Amines
• Oils/fats
• Sucrose/glycose
• Additives in fuel

Why Does NIR Matter?

Since the 1960s, NIR has increasingly become the measurement method of choice for low-cost, rapid, non-destructive, measurement of various constituents in food, agriculture, paper, packaging, pharmaceuticals, frac sand, and other powders and bulk materials. The key to NIR’s success is its accuracy without any preparation of the sample. Most other types of measurement are more expensive, sensitive to fluorescence, or require sample preparation to be accurate.

NIR enables on-line, real-time measurements, so operations can spot process problems early and adjust production parameters to optimize quality and throughput. In many cases, NIR is one of many sensors that exist on highly automated manufacturing lines that require precise tolerances for quality final product.

Process automation with quality NIR sensors is critical to driving energy efficiency, product quality and manufacturing throughput. Companies that don’t embrace tools such as NIR and other sensors are left behind as competitors increasingly adopt this incredible technology. Combined with an IOT and AI strategy, NIR is an important tool used by manufacturers throughout the world and saves hundreds of thousands of dollars in lost time, labor, and product.