Process Sensors Corporation

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Frequently Asked Questions about NIR Measurement in Tobacco

Which are your most commonly used moisture meter models? Why are these particularly popular?  

The near infrared (NIR) MCT460-T tobacco moisture transmitter is our most commonly used moisture meter due to its high performance, system flexibility and economical price. The transmitter may be used as a stand-alone transmitter feeding directly into a network, or as a system with local Operator Interface and Display that can also feed into a network. The dual core architecture, built-in data logger, optional infrared (IR) temperature sensor and embedded bootloader have made the MCT460-T the preferred choice for new and upgrading tobacco lines.  

Our prior MCT360-T was been the workhorse in the tobacco processing industry for many years as a result of its ease of use and low cost. It has now been replaced with the next-generation MCT460-T, a direct drop-in upgrade for the MCT-360-T, conveniently using the same wiring and cabling. 

Furthermore, our MCT466 QuikCheck is rapidly expanding in the laboratory and at-line markets providing immediate moisture measurement of grab samples.  

What are the main challenges when developing a tobacco moisture meter? 

The main challenges in designing a moisture meter are the incorporation of robust electronics for the environment, ease of use for both high level engineers and line operators and flexibility in design of digital interface and analog outputs. The NIR wavelengths and detectors to measure tobacco moisture have been long documented and published. The art is in the robust housing and the flexibility to meet the customer’s expanding needs for data collection and remote diagnostics via digital interface.  

What are the main differences between offline and online meters? Their advantages? Their application areas? 

Online meters provide process measurements that can be used for alerts, alarms and control in the manufacturing process. They generally include a large local display of moisture that the operator can view and immediately notice if it’s in normal (green display), alert (yellow) or alarm (red) range. Online meters will also supply a digital interface and analog outputs.  

Offline meters are generally either at-line or in the laboratory dependent on the need. The MCT466-QuikCheck can be used in the lab to increase sample throughput for quality assurance and feed into a LIMS system via digital interface. It can also be used at-line to quickly measure grab samples from multiple lines and unit operations at the process line.   

Do you also have models that are capable of measuring nicotine and sugar content? Which models? In which circumstances do tobacco producers prefer to have these measuring capabilities integrated? 

Tobacco and tobacco processing include many chemicals that complicate the measurement of nicotine and sugar in the Near Infrared. Unlike the sharp peaks in the IR region, NIR measures broad bands that make it difficult to discriminate specific reducing sugars. Online, NIR meters can provide nicotine and sugar content as a trend at best due to real process and blend variations. Better results can be obtained in the lab where the sample presentation is better controlled, though more traditional laboratory methods may better suit the customer’s needs.  

Is it important to take air temperature and air humidity into account when measuring? Why is this important? 

Unlike radio frequency (RF) and di-electric measurements, air temperature and humidity have little impact on NIR tobacco moisture measurement. Transmitter electronics operate reliably in ambient temperatures up to 50⁰C (120⁰F). Ambient temperatures above 50⁰C can be addressed with vortex air cooling for up to 80⁰C (160⁰F). Humidity doesn’t absorb in NIR ranges and only poses a problem with condensation. A built-in fitting allows for an air purge of 3-5 psig to protect the lens with a laminar flow in dusty or highly humid environments. 

How easy is it to calibrate your machines to be used with different tobacco blends? How is calibration accomplished? 

Most NIR tobacco moisture meters arrive at the plant pre-calibrated based on a large library of calibrations and only require a zero test for offset confirmation or adjustment. Calibration is very easy with the MCT460-T. Calibrating an analyzer typically compares the lab vs. meter measurement with 3 to 5 samples across the range of interest for each product family. A simple linear regression is performed on the data calculating the slope and y-intercept. The MCT460-T automatically calculates and uploads the new zero (y-intercept) and span (slope) for proper calibration.  

What type of sensor technology is commonly deployed in your machines? Does this type of sensor have advantages over others? Which? 

Our technology employs NIR absorption principles to make an accurate, fast and reliable tobacco moisture measurement. The MCT series sensors feature easy calibration, operation, standardization and low maintenance to offer the best return on investment with no government regulations. Our sensors distinguish themselves from other NIR units with the ability to vary filter speed, detector temperature and with the inclusion of built-in data logging. The software platform includes dual core technology with one core dedicated to NIR signal acquisition and one core to manage computations and communications. NIR is not impacted by ambient temperature and humidity that can hamper RF, di-electric/capacitance and microwave systems. 

What are the different measuring parameters required for a) tobacco leaf, b) primary tobacco product, c) finished tobacco product, d) reconstituted sheet tobacco? 

Tobacco moisture Is critical in all phases of tobacco processing. Moisture impacts smoking quality, flavor, burn, fill, waste and machine operation from green leaf threshing to primary processing. Each operation such as drying, re-moisturizing, rolling, cutting and conditioning have an optimum moisture level to maximize efficiency. The moisture parameters for the different tobacco processes vary only in moisture level targets for each operation. Leaf tobacco can run up to 45% or higher moisture; primary, 12-18%; finished, 5-8%; and recon, as low as 2-6% moisture.  

Do you currently have a model that can handle all above product types, or is a different machine required for each? 

The MCT460-T Moisture Meter is designed to meet all tobacco moisture needs for each line and unit operation.  

Has your tobacco moisture meter business experienced growth in recent years or have retractions/restrictions in the tobacco product markets had an impact? 

Our tobacco moisture meter business continues to grow with expanded manufacturing and tobacco process-line instrumentation upgrades. The process instrumentation upgrades are a result of new features such as digital interface and archiving, and possibly the restrictions in tobacco product markets driving a new and pressing need to improve efficiencies in the manufacturing process.  

If you have a question that wasn’t answered above, please fill out the contact form below and one of our application experts will reach out to discuss your inquiry or application.