A fit-for-purpose near-infrared (NIR) analyzer for quality-by-design (QbD) manufacturing

The MicroNIR™ PAT-W is a rugged, battery-powered NIR spectrometer equipped with WiFi data communication and designed for use on rotating blenders and stationary process equipment.

The MicroNIR PAT-W spectrometer is a fit-for-purpose near-infrared (NIR) analyzer for quality-by-design (QbD) manufacturing. The spectrometer is a sturdy, scalable, next-generation system for real-time process monitoring in blend homogeneity, content uniformity, loss on drying, roller compaction, and similar process analytical technology (PAT) applications. With the well-established Viavi linear variable filter (LVF) technology, the PAT-W has the smallest form factor among commercial process monitoring instruments in a fit-for-purpose design. This makes it ideal for use with processing equipment of a variety of sizes, with the stability and performance to facilitate efficient and smart manufacturing.


The user-friendly MicroNIR PAT-W was engineered to handle today's challenging GMP-regulated environments yet requires minimal system maintenance. There are no expensive fiber optic cables or moving components, enabling superior instrument stability and performance in challenging process environments. Its stainless steel/brushed aluminum case is water and dust resistant according to IP65/67 standards.

Key Features

The key features of the MicroNIR PAT-W spectrometer are as follows:

  • Non-destructive, non-invasive, and real-time near-infrared analysis

  • User-selectable Ethernet or Wi-Fi for data communication and system control

  • User-replaceable, rechargeable Li-ion battery with over eight hours of uninterrupted run time

  • Integrated PC enables fast and secure store and forward of spectral data

  • Incorporated multi-axis orientational triggering

  • Trigger options for a variety of applications: push button, OPC and external photosensor

  • Real-time moving block standard deviation (MBSD) analysis for endpoint determination in granulation, blending, drying, and coating processes

  • Washable, IP65/67-rated enclosure


Applications of the new MicroNIR PAT-W spectrometer include:

Pharmaceutical Manufacturing

  • Blend & content uniformity
  • Fluid bed drying
  • Granulation

Food and Feed Manufacturing

  • Moisture content
  • Nutritional assay
  • Protein, fat & fiber

Industrial Processing

  • Polymers
  • Reaction monitoring
  • Petrochemicals

MicroNIR Software

The included MicroNIR Pro software suite has features for data acquisition, calibration and method development, user management, and real-time prediction. MicroNIR Pro can build and apply complete chemometric models using regression and classification algorithms including PLS, Moving Block, SMV, and PCA analyses. Batch mode predictions on stored data are also supported.

Options include an enhanced OPC interface for integration with process control systems and prediction engine add-ins for Camo Unscrambler, Eigenvector Research Solo Predictor and Sartorius SIMCA chemometric software.

Mounting and Process Integration

VIAVI offers multiple options for interfacing the PAT-U to process equipment via standard sanitary flanges and weld-in flanges with a sapphire process window that separates the MicroNIR from the material being analyzed.


This includes a weld in base flange, a 2” sanitary (hygienic) flange mount, a sapphire window, and a retaining ring with O-rings. The base flange is welded into a hole cut in the lid of a blender and then the sanitary flange mount, window, and retaining ring are assembled. Next, the PAT-W with an adaptable collet is secured against the window and a sanitary flange using a standard tri-clover clamp (or C-clamp). All pieces can be dismantled for easy cleaning and maintenance.


The threaded mount allows a user to weld a mount into the process equipment and then link the PAT-U using the threaded tip of the spectrometer. This mount also has a removable window to allow easy cleaning and maintenance.


Standard lid mount kit with weld-in flange

The PAT-W has an integrated nine-axis inertial measurement unit (IMU) that consists of a three-axis gyroscope, a three-axis magnetometer, and a three-axis accelerometer. The IMU enables highly accurate and repeatable triggering of spectral acquisition by the PAT-W when mounted on a rotating blender.


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Illumination source

Two integrated vacuum tungsten lamps

Bulb life

>40,000 hours

Illumination geometry

Flood illumination/ 0° observer

Input aperture dimensions

2.5 x 3.0 mm

Sample working distance

0-15 mm from window

Dispersing element

Linear variable filter


128-pixel InGaAs photodiode array

Pixel size/pitch

30 µm x 250 µm/50 µm

Wavelength range

950 – 1650 nm (10,526 – 6060 cm-1)

Pixel-to-pixel interval

6.2 nm for 950-1650 nm

Spectral bandwidth (FWHM)

<1.25% of center wavelength (1% typical) (for example, @1000 nm, resolution is <12.5 nm)

Analog-to-digital Convertor

16 bit

Dynamic range (max)


Measurement time (typical)

0.25 – 0.5 second

Integration time

10 ms typical, minimum 10 µsec, maximum limited by dark signal

Computer interface

TCP/IP Cat5 Ethernet 802.11 g WiFi

Spectrometer weight

Less than 1.4 kg (3 lb)


160 mm x 136 mm x 136 mm
(6.3 in x 5.37 in x 5.37 in)


Battery: 7.5 V @6.4 Ah for >8 hr run time
External: 110-240 V AC

Data format

Encrypted, Unsb, CSV, and SPC output

Operating system

Windows 8.1, 8, and 7

Software available

MicroNIR PAT, Unscrambler X Lite, MicroNIR Process

Operating temperature

0 – 40 deg C (non-condensing)


Stainless steel and aluminum: dust and waterproof, sealed and cleanable to IP67 standard


Internal 9-axis IMU, external 24 V input


Adaptable stainless steel tri-clover mount