Chemical and Pharmaceutical Applications
|Acetate Tow and Sheet
||Powders (in or post spray dryer)
|Chemical powder formulations
||Plastic powders, granules and beads
||PVB laminated glass
|Explosives, e.g. nitrocellulose
For “in-process” installations, that is viewing product through either a sapphire viewing window, via the use of a powder sampler or sample probe, the MCT 360-FG with either an electroless nickel or stainless enclosure and kelF or sapphire window is one option, the alternative is a stainless steel enclosed MCT 366 which operates without sensor cooling to 65 °C. In instances where there is the potential for explosions owing to the presence of powder or volatiles, an Atex 22-MCT 360 and MCT 360-Exd are available. A standard MCT 360 in a painted cast aluminium enclosure with a glass window is suitable for many chemical applications provided the environment is non corrosive.
An MCT 660 is recommended for At-line analysis. The integrated unit can be connected to a serial printer to provide a printout of moisture content % product calibration used and time and date for each sample as it is analysed. The sample is rotated to maximise the measurement area and provide a truly representative moisture reading.
A glass or sapphire sight window mounted within a metal flange can be installed in a metal chute, storage silo or fluid bed dryer provided there’s sufficient product to cover the window. A sample probe can be inserted into the middle of a vertical stream of product, and a powder sampler can be used to collect product of low density. A product high/low alarm board is an option that can be simply fitted to provide an audible or visible alarm should either limit be exceeded.
A vortex cooler is available should the ambient temperature exceed 50 °C.
In the event of discontinuous flow of product, one or two product loss sensors will enable the gauge to update measurements only when the gauge is viewing product.
Gauge outputs, Operator Interface & Display
All outputs are direct from the moisture sensor head in the MCT 360, and from the operator interface in the MCT 366. Network options; Ethernet, profibus and devicenet are available in addition to the standard 4-20mA, 0-10V, RS232 or RS485 outputs. An OI is available for display and programming purposes, but isn’t essential. MCT Viewer s/w can be used as an alternative means to program the gauge.
Pharmaceutical powders are typically consistent in colour, composition and particle size and thus can be measured to a high accuracy ( 0.05-0.1% ) provided they are thoroughly mixed, this is very important in the case of products containing more than one active ingredient. Poor mixing or clumping of particles will lead to more variable results. Near Infrared moisture measurement can be used not only to control the end point of the batch drying cycle but also to control the wet granulation, blending and tablet coating processes.
The accuracy of a moisture measurement in chemicals will depend upon colour, transparency, lustre, particle size variation and chemical formulation.