NJK
Precision
Patented dual-chambered airfoil airflow measuring stations and damper louver solutions — inspired by aviation and automotive technology to deliver NIST-certified accuracy down to 50 FPM in any HVAC application.
Airflow Measuring Stations (AMS)
NJK Precision’s patented airflow measuring stations are built around a dual-chambered airfoil design — the same physics principle as an airplane wing — to dynamically normalize turbulent ductwork flows and deliver unmatched measurement accuracy in even the most restricted installations.
The core NJK product — a perimeter-installed Flow Frame with patented dual-chambered airfoil design. Two frame sizes minimize duct cross-section impact. Available for new construction and retrofit.
- Small frame: 2.75″ wide (ducts under 18″)
- Large frame: 5.5″ wide (ducts 18″ or greater)
- Reads down to 50 FPM airflow velocity
- Place just 1 duct diameter from 90° elbow
- ±0.19% uncertainty at 95% confidence (NIST)
- 1–10 VDC output to BAS; signal in SCFM
Round station version of the NJK airfoil technology — single station covers a range of circular duct diameters through adjustable mounting bracket assemblies, minimizing SKU requirements.
- Adjustable mounting — one station fits multiple diameters
- Same dual-chambered airfoil sensing principle
- Thin film resistor Flow Measuring Module
- NIST-traceable calibration (25–37 flow points)
- RJ-45 watertight probe/transmitter connections
- Signal dampening for high-transient & crosswind applications
An economical multi-station solution not available from competitors — one SPU-M monitors up to 8 airflow stations simultaneously, replacing the need for a dedicated display per sensor.
- Up to 8 stations per SPU-M via Multi Sensor Hub
- Monitor 4 airflow values simultaneously from one location
- 24V AC or DC powered
- Four 1–10 VDC outputs to BAS
- Total cable run up to 300′ per SPU-M
- Airflows can be summed for totalization
Damper Louver Solutions (DLS)
NJK Precision’s next generation of precision airflow monitoring — designed to mount immediately adjacent to dampers and louvers with lifetime calibration and ultimate placement versatility.
Install Right Next to a Damper or Louver
The DLS raises the bar on ease of installation, placement flexibility, and performance. Unlike conventional stations that require clearances, the DLS mounts immediately next to a damper or louver without compromising precision accuracy — even in non-uniform, non-laminar, or turbulent airflow.
DLS Key Features
Installation
- Mounts immediately next to a damper or louver
- Interior and exterior applications
- Single sensor design reduces costs
- Minimizes airflow restriction
- Plenum-rated communication cables
Design Components
- U-Frame with active airfoil uprights (linear ports)
- Inert airfoil ported to Flow Measuring Module
- End caps with dual pressure isolation
- Dual chamber corners and T-couplers
- Plug & play Flow Measuring Module
Operations
- Lifetime calibration — no re-cal needed
- Minimal inspection and cleaning only
- Single-sensor avoids degrading sensor data
- Advanced thin film thermal dispersion technology
Performance
- Precision accuracy at any flow rate
- Works in turbulent and non-laminar air
- No aggregate data issues
- Longer sensor life cycle
The NJK Precision Difference
Aviation-Inspired Airfoil Design
The dual-chambered airfoil Flow Frame works like an airplane wing — air momentum over the frame creates differential pressure proportional to mass flow, dynamically normalizing turbulent ductwork airflow.
NIST-Certified ±0.19% Accuracy
Each Flow Measuring Module is calibrated across 25–37 flow points on a primary NIST-certified testing stand. Uncertainty is 0.19% at 95% confidence — accurate in all temperature and humidity conditions.
Minimal Placement Restrictions
NJK stations can be placed just 1 equivalent duct diameter from a 90° elbow — vs. 3 required by conventional stations — dramatically expanding retrofit and new construction options.
Automotive MAF Sensor Technology
The thin film resistor sensing module uses the same mass airflow (MAF) sensor technology proven in fuel-injected automotive engines for decades — delivering reliability and sub-50 FPM low-flow sensing.
Low Flow Measurement to 50 FPM
The NJK AMS reads accurately down to 50 feet per minute — enabling precise outside air control even when supply fan speeds are reduced, supporting ASHRAE and IAQ compliance at low loads.
Fast Field Assembly — Built to Order
Stations ship unassembled to reduce freight cost and prevent damage. Slip-fit field-adjustable corner pieces connect sections in minutes. Frame is adjustable +0.5″ to +1.25″ to accommodate actual duct dimensions.
Specify NJK Precision for Your Project
With 21 patented claims and NIST-certified accuracy to 50 FPM, NJK Precision is the right choice for demanding airflow measurement. Contact CEE for specifications, submittals, and support.