Digital electronics and precision engineering contribute to the small size of the latest addition to Process Sensor Corps.? IR thermometer line.

The DS-40N or DG-40N series of stainless steel pyrometers are 124.5mm long overall by M40x1.5 threaded diameter, operates in a loop powered mode to produce a linear 4 to 20mA output, over selected temperature ranges from an overall span of 250 to 2500?C in two models.? In a 4 wire mode, the sensor also offers green LED, illuminating the exact target size, or laser aiming.

Depending on the model, either DS-40N or DG-40N, and temperature range, selected optics provide small target, close focus e.g. 1.2mm diameter at 210mm distance, or extended focus out to 4m with a 20mm diameter target.? A USB connection gives access to PC adjustments of such parameters as emissivity, response time, temperature sub-range and peak picker, with supplied software.

Without cooling, the non-contact temperature sensor will operate in ambient temperatures up to 70?C, and in higher ambient of 200?C with the optional cooling and lens-purging jacket.? The Model DS-40N has a spectral response of 0.8 to 1.1?m, and the DG-40N 1.5?m to 1.8?m, for minimum vulnerability to variable target emissivity, and to optimize the effective emissivity of low radiance targets.

The temperature ranges, optics, rugged construction and signal processing capability will appeal to users in the Steel, Ceramics and Glass Industries, Cement and Refractory manufacture, Induction Heating and Sintering operations.

Process Sensors? ?PSC Spot Software? supports sensor set-up, multi-tasking, graphic display of temperature trends, and data logging, and in general allows the user to customize the sensor to the application.

Detailed specification information can be found at


PSC-SSS laser small


With an overall size of only 4? (100mm) long x 2.2? (55mm) dia, Process Sensors? latest addition to their family of compact, non-contact, on-line temperature sensors features dual, converging lasers that brightly illuminate the exact location of the target spot at any distance from the lens.? This feature greatly simplifies sensor aiming, and eliminates ambiguity that could result in error readings.

The Model PSC-SSS-Laser-3M offers a wide overall temperature span of 50 to 600?C, a short wavelength, spectral response of 2.3?m, and selectable target spot sizes from 1.75mm at 70mm distance, 90mm at 3600mm, 0.7mm at 70mm or 36mm at 3600mm, depending on the selection of optics and model.? The specification particularly suits the thermometer to secondary metal processing, and the measurement of oxides and ceramic materials.

Signal processing and programming electronics are contained in a rugged 2.75? X 3.5? (70 x 89mm) housing that can be mounted up to 9.8 feet (3m) from the sensor as standard, or optionally 26 feet (8m) or 49 feet (15m), providing greater immunity from electromagnetic interference, mechanical shock, and high ambient temperatures.? The sensing head is able to withstand ambient temperatures of up to 85?C without cooling.

Functions provided by the signal processing and programming unit include: analog outputs of 0/4-20mA, 0-5/10V, and J and K thermocouple.? Optional digital outputs are: USB, RS 232, RS 485, Profibus DP and Ethernet.? Programmable parameters include emissivity and transmissivity adjustments, peak and valley hold, averaging, and extended hold with threshold and hysteresis.

Process Sensors? ?PSC Spot Software? supports sensor set-up, multi-tasking, graphic display of temperature trends, and data logging, and in general allows the user to customize the sensor to the application.? More information can be found at

Process Sensors Corp. is a private company with manufacturing facilities located in Milford, MA.? The company manufactures temperature and moisture instruments, and associated calibration systems.? Technical and application support is provided throughout the USA, Great Britain and Eastern Europe.

The Pellet Making Process And The Importance of Moisture Monitoring

Moisture control is one of the major challenges for pellet plant operators.? PSC offers a solution with an online sensor that provides continuous moisture measurement through out the process.? ? Being proactive with moisture measurement offers cost savings in the manufacturing process and eliminates the chance of packaging wet or low quality product.? It is Process Sensor’s goal to help the mill make a high quality pellet by providing state-of-the-art moisture measurement with NIR technology.

Waste sawdust and wood chips are delivered to the pellet plant by truck or rail car then stacked outside in large mounds.? A front loader is used to take the sawdust from the different piles and load the feed system for the plant.? Wet and dry sawdust is selected by the tractor operator in an attempt to keep a moisture balanced load heading into the dryer system.? This green wood generally has a moisture content of 20 to 50%.? If the sawdust is stored outside the moisture can be higher or lower depending on the weather.? It can be a challenge for the loader operator to keep an even mix of wet and dry sawdust going into the feeder system.

A Process Sensors Corp. moisture meter is very helpful to the loader operator as a sensor is mounted on the screen infeed conveyor and a large display is mounted outside for the operator’s use.

This first step in the process is to screen the sawdust and wood chip mixture to separate the fine chips from the coarse chips.? The coarse chips are ground to reduce their size for quick and even drying.? They are then remixed for temporary storage.

After a second screening to separate the fines from the coarse, the coarse chips are reduced in size with the hammer mill.? The hammer mill output and fines are again mixed and stored in bins by moisture content.

The sawdust is then conveyed into a large drum dryer where the moisture is reduced to less than 10%.? The sawdust is then conveyed into a cyclone dryer where high speed swirling air removes additional water vapors and cools the product down.

A PSC moisture meter is typically mounted on the dryer where the moisture is reduced to less than 10%.? If the moisture is higher than 10% the sawdust will be directed to a moist bin.? Typically, moist bins and dry bins will be blended for the ideal moisture level going into the pellet process.? Use of PSC moisture meters on each of the bin outputs can offer additional information to aid in the blending process.

One of the most important measurements is of the final mixture after blending and prior to the press.? A PSC moisture meter is used to continuously measure this moisture level going into the pellet mills.? The analog output signals from the sensor can be used to forward feed a PLC.? The PLC can be programmed to take control of the power level and speed of the press thus creating a more consistent product.? This mixture is now ready to be pressed into pellets or sent back to the dryer as fuel for the burner.

The processed sawdust is conveyed into the pellet press where the pellets are formed under very high pressure.? This high pressure drives off additional water and causes the natural wood lignite to bind the sawdust into shiny hard pellets.? After the pressing, the finished pellets go through one final screening to recover any leftover sawdust for recycling.? The cooled and screened pellets are stored in silos while waiting to be bagged and shipped.? The standard package is a 40lb moisture protected bag for household heating.

Hot Melt Adhesives

The MCT 360 can measure hot melt adhesives on paper, board and textiles. Hot melt adhesives are typically solvent free thermoplastics, they melt or decrease in viscosity at temperatures in excess of 180o F, then rapidly set upon cooling. They can be repeatedly softened by heating, and hardened by cooling, this property makes them very useful in discontinuous manufacturing processes where one of the 2 substrates may be applied in
a separate location. Different polymer systems are used to form hot melts depending upon the application:

Acrylates (hot melt PSA) are used in packaging and construction
Styrenes (SIS and SBS) are used in pressure sensitive applications
Polyamides are used in high strength hot melt adhesive systems
Polyethylene (PE), Polypropylene, and other olefins are used for a variety of applications
Polyurethane (PU) adhesives are used in applications where excellent flexibility and durability
are required.

Measurement of coat weight is important for 2 main reasons:

1. Adhesive coating needs to be uniform to provide a high coefficient of
adhesion between the two substrates.
2. For cost effectiveness, the aim is to apply the minimum quantity of coat
weight in order to achieve adhesion.

Manufacturing Process

Polymer granules are apportioned into an extruder whereupon they are melted, and applied with a doctor blade into the engravings of an engraved roller through a slit die, before being applied to the substrate. Alternatively the molten adhesive is extruded through a slit die onto the substrate at the nip between a pressure roll and a metal chill roller.

Measurement Locations

Measurement is made immediately after the chill roller, on the set adhesive. The gauge should be mounted approximately 8 inches from the surface of the web.

Measurement Performance

Measurement ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Range %? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Typical Accuracy %

Hot-melt adhesives? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 10-50 gsm? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? +/- 0.3 gsm

Moisture Measurement in Gypsum Board

Process Sensors will be attending the 9th Global Gypsum Conference for the global trading, marketing, production and processing technology of gypsum.? An application sheet explaining the importance of moisture measurement in gypsum board follows:

The Importance of Moisture Measurement in Gypsum Board

The durability, strength and hardness of finished board is heavily dependent on moisture content. Measuring moisture content not only improve quality, but ensures ongoing product consistency, resulting in fewer reject boards and saving on rework costs.? RFM-1000, Process Sensors? on-line RF sensor, measures moisture, enabling optimization of the production process through feedback and/or feed forward control of the temperature set point within the different kiln zones. Process optimization maximizes quality product throughput, saving on energy & raw materials and also indirectly on labor and plant costs.

Gypsum Board Production Process

Gypsum (CaSO4.2H2O) is obtained either naturally from gypsum deposits in the ground, or synthetically as a byproduct of another process. Most synthetic gypsum is derived from Flue Gas Desulphurization (FGD) of fossil burning fuel power plants. Board can be manufactured from natural gypsum, synthetic gypsum or a combination of the two. Regardless of the derivation of the gypsum, it is crushed, dried, ground to a fine ?flour,? then calcined to drive off all the chemically combined water as steam. Water and other ingredients, e.g., sand and fire retardants, are added, and the wet mix is pumped to a conveyor whereupon it is sandwiched between 2 layers of paper. The board sets as it?s conveyed towards the kiln, is cut into drying lengths and loaded onto a deck within the kiln. The dryer comprises 3 or 4 temperature zones. Upon exiting the kiln, the board is cut to final length, trimmed then packaged.

Sensor Details & Installation

The RF sensor comprises a 30, 60 or 90cm aluminium antenna with teflon spacers, cabling and operator interface. Temperatures exceeding 50? C necessitate the use of aluminium/ceramic antennae, and 260? C; stainless steel/ceramic antennae. Coax cabling is required for all applications where ambient temperature exceeds 60? C. Sensor mountings are constructed from stainless steel. Owing to the differential expansion coefficient of aluminium and steel with temperature, the aluminium sensor is only fixed at one end within the kiln. The other end is free to expand horizontally eliminating the potential for dryer blockages owing to the sensor bowing upwards. The sensor is located 6mm below the bottom face of the board, and requires good clearance beneath, to allow debris to fall through the open frame enclosure.

RF Moisture Measurement in Gypsum Board

Within the dryer, the sensor is normally located on a representative deck, usually deck 4 or 5 in an 8 deck dryer. Sometimes the sensor is located on a wetter deck to most quickly eliminate the source of reject boards. However, this could cause burning on the drier decks unless the kiln is balanced.


The RFM-1000 generates a RF fringe field of approximately 2 MHz into the board. The board conductance changes with water born dielectric variation, and this produces a raw dielectric value that is directly proportional to the moisture content of the product. Moisture can be measured in the range 0-80%, but will require different calibrations for low, medium and high moisture levels. Radio frequency measurements are not influenced by changes in PH and dissolved salts, but are affected by shifts in distance between product and sensor, density changes and appreciable temperature changes. Pass height variation is not of concern when measuring on the lower edge of the board. Compensation inputs are available for density and temperature changes if required, but all that is typically needed is a change of calibration when switching between products of different thicknesses. The sensor features high speed measurement capability, up to 200 measurements per second, and together with the automatic product loss and return measurement hold signal, this enables the output of individual board moisture averages.

Induction Heating Applications

After unsatisfactory experiences with competitive pyrometers, this nationally known manufacturer of fasteners for aerospace applications recently installed fifteen Model PSC Sirius SI16 pyrometers on their Inductoheat, Ameritherm, and Tocco induction heating machines.

The machines pre-heat high-duty alloy blanks that are then forged into fasteners used in aircraft and space module construction.? The accuracy, precision adjustable focus and laser aiming of the Sirius pyrometer is critical to ensure correct temperature and heat distribution in the blanks.? This is essential to avoid post-forging stresses that could give rise to fastener failure in use.

A company spokesman, who selected the PSC? Sirius SI16?s over the competition, stated that ?The Process Sensors product was the only one that met or? ? exceeded our rigid requirements in the manufacturing environment.? All the pyrometers have performed flawlessly.?

The Application

Induction heating uses high frequency electromagnetic energy to rapidly heat metals. Application constraints typically include confined sighting paths, small targets, variable emissivity surfaces, smoke in the sight path and strong magnetic fields.

The design features of the Sirius pyrometers are aimed at eliminating or minimizing the impact of these factors on the measurement.? The narrow, short wavelength spectral response reduces errors due to variable emissivity.? Adjustable focusing and laser aiming simplify sighting on specific areas of the product, while avoiding partial obstructions in the sight path.? Digital signal processing and careful electronic design minimize magnetic interference.

The Market

Induction heating machines are common across manufacturing industries wherever metals are heat treated or formed.? The fastener industry, auto and aircraft components manufacturing, tool making and
pipe forming, as examples, all use a multiplicity of induction heating systems.

This processing method is also found in less obvious applications such as rebar coating and bearing manufacturing.

Many induction heating OEM?s have traditionally used competitive IR sensors, but it is clear that the high accuracy SI16 with wide temperature range, small spot size, adjustable focus laser aiming, standard analog and digital output capabilities make this the preferred sensor of choice in the induction heating marketplace.

Model No.: PSC?s Sirius SI16-0300-1300-1-2-2-5-1-A

Temperature range: 572?F to 2372?F ( 300 to 1300?F )

Process Sensors Attends SNAXPO 2009

Process Sensors attended the SNAXPO 2009 Show held March 29-April 1 in Orlando, FL to demonstrate instruments showing the importance of measuring moisture and oil in snack food manufacturing environments.  According to the Snack Food Association, ?More than 100 exhibitors filled the SNAXPO show floor offering new ideas, products and services for snack food company decision makers seeking to build their businesses.?

An application sheet explaining the importance of measuring moisture and oil in potato chips follows.

Measuring Moisture & Oil in Potato Chips

The continuous measurement of moisture prior to packaging is a key consideration in the production of potato chips.? The proper moisture level of finished chips helps guarantee taste, texture and shelf life.

The use of NIR (Near Infrared Reflection) moisture gauges in snack food manufacturing environments has become an accepted technology for monitoring and control.? The on-line measurements are instantaneous and non-contact.? Any change in moisture level can be immediately recognized by the use of a Process Recorder, eliminating the potential for customer quality complaints or waste.

NIR can also be used to measure oil content, along with moisture.? The oil measurement is most often done at-line as a quality indication prior to packaging.

Chip Manufacturing Process
Potatoes are peeled, sliced and de-starched prior to Frying and Seasoning. Measurements of oil and moisture are typically made shortly after the exit of the Fryer. Moisture measurement at the exit of the Fryer can be used to optimize moisture %, this results in greater product consistency, longer shelf-life and less waste material.

Transmitter Installation
PSC moisture transmitters should be located after the fryer outlet, over the vibrating conveyor.? The transmitter should be mounted 10? from the surface of the potato chips.? Heat at the fryer outlet can create very high temperatures.? If the transmitter must be located close to the outlet of the fryer, it is important to consider cooling.

The MCT330SF moisture transmitter is designed to measure moisture, oil and product temperature in a food processing environment. The transmitter is housed in a stainless steel enclosure and employs a food grade optical window. The MCT is optimized with filter combinations to measure moisture and oil at the same time.? The viewing window in the sensor is a food grade polymer.? The stainless steel housing is sealed so that the NIR sensor can tolerate a wash-down environment.

The MCT-330SF is fitted with an air purge assembly to prevent oil or moisture from depositing on the sensor?s lens.? The Stainless Steel Enclosure can also be fitted with a Vortex cooler in the event of a very elevated temperature environment.

Measurement Performance
Moisture measurement in potato chips is a very well understood and documented application. NIR wavelengths, algorithms, and sensor optical parameters are pre-set at the PSC factory.

A calibration is entered into the MCT-330SF at the PSC factory.? There is no calibration required after installation on the processing line.

It is important to locate the MCT so that there is always product beneath the NIR sensor.? The measurement works by detecting reflected light.? The light must be reflected off of the product, not the vibrating conveyor!

Breakfast Cereal Applications

Knowledge of the moisture content at the exit of the cooker, cooker extruder and exit of the

toaster, yields important information which can be utilized to maintain the consistent form,

taste and texture of the cereal in addition to optimizing product yield, reducing scrap and

saving on energy costs. On-line measurements give instantaneous information, enabling

tighter process control than can be obtained through lab analyzed data.

Cereal Production Process

Processes vary, but one such example might contain: a Mixing stage where dry and liquid

ingredients are mixed, Cooker, Extruder or Former, Cutter, Cooler, Flaking Roll,

Dryer-Toaster, Froster-Sprayer and Dryer.

Measurement Location

Moisture measurement at the exit of the Cooker, prior to the Former, reduces the quantity

of misshapes through product sticking or disintegrating in the flaking process. Moisture

measurement post Toaster enables maximization of final moisture, this optimizes yield,

without compromising taste, texture and shelf life characteristics.

Gauge Installation

Typically the gauge is installed over a conveyor, approximately 8? from the product. It is

important to maintain sufficient product bed depth to cover the conveyor, and continuous

product flow, especially if the gauge is used in closed loop control of the toaster or dryer.

The gauge is best positioned at a location several feet from the exit of the toaster/dryer as

this gives the product a chance to reach a degree of equilibration. If possible

measurement should be made on well mixed product; an ideal location is after a short drop

from one conveyor onto another.

The Food Grade MCT300 incorporates a food grade electro less nickel enclosure and either

a kel F polymeric, or sapphire viewing window. An optional water/air cooling panel or vortec

cooler are available if the ambient temperature exceeds 55?C.

Measurement Performance

Application Notes

Moisture in Breakfast Cereals | ?2005 Process Sensors Corp.

Measurement Location Target % Typical Accuracy %

Moisture Exit Cooker 20-30% 0.4%

Moisture Exit Toaster/Dryer 2-8% 0.15%