Accessories
Installations at high temperature locations may well require
a vortex
cooler and cooling
panel. Product
loss sensors are required for measurement on discontinuous
product, e.g. egg cartons.
Gauge outputs, Operator Interface
& Display
The MCT
360 is available with or without a local operator interface
or display as all the processing is carried out within the
sensor head and the measurement is output via 4-20mA, 0-10V,
RS232, RS485 or any bus. Installation time and effort is minimised
by dispensing with a local OI, but should samples be collected
for cross checks an OI is useful… in this event, one
could be simply plugged into the gauge at the sampling location.
The Measurement
Measurement of glossy or wet surfaces requires the gauge to
be angled approximately 17° to the product to eliminate
spectral interference (reflections) from top surface. A passive
reflector, e.g. a glazed white tile or a Teflon Strip is required
to maximize the detector signal in the event a gauge is viewing
transparent or semi-transparent (scattering) material.
Moisture , coat weight, and product
temperature can be measured using NIR. Please note that thickness
measurements, other than those of a transparent monolayer
film are not feasible.
Moisture is measured at various stages
throughout the paper making and converting process, also in
corrugated paper and egg cartons. Various coating materials
applied to either a paper, textile or plastic film substrate
can be measured at either the wet end ( immediately after
the applicator) or at the dry end. The MCT
360 measures both moisture and coat weight. If a coat
weight measurement is required this can be performed either
at the wet end (immediately after it has been applied) or
at the dry end, after it has gone through a dryer, over a
chill roller or through a curing process. The choice of dry
or wet end measurement is dependent upon several factors:
• Whether the dry coating
material absorbs in the NIR or not.
• Best location for
process control
• Simplest Installation location
• Measurement location that provides the lowest measurement
error. Note that NIR is generally more sensitive to changes
in moisture than organic (C-H) content, hence, even if the
solids ratio is higher than 50%, a wet end aqueous measurement
may still be the best choice.
Product temperature can be measured
at any stage of a process.
Gauges are delivered pre-calibrated
using customer samples when possible. Wet end measurements
cannot be reliably pre-calibrated so must be set up once installed.
PSC offers on-site commissioning and/or training. |
