Michell Instruments Optidew Specifications

Chilled Mirror Instruments

Optidew

Chilled Mirror Hygrometer

The Optidew is a fast-responding chilled mirror hygrometer, equally at home in both industrial
humidity control and precision laboratory applications. It is available in bench top and wall mount
confi gurations, and features an intuitive touch screen interface for easy local operation. Using the
latest developments in chilled mirror technology, it has a response speed comparable to polymer
relative humidity sensors, combined with the reliability of drift-free measurements common to all
chilled mirror instruments.

Highlights

• New chilled mirror hybrid sensor gives fast
dynamic response to changes in humidity

• Accurate to ±0.15°C dew point, ±0.1°C
temperature

• Wide measurement range from -40 to +120°C
dew point

• Choice of communication methods, including
Modbus TCP over Ethernet communication for
easy networking

• Optional pressure transmitter for accurate
calculation of ppm

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& g/kg

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Applications

• Reference humidity instrument for climatic and
environmental chambers

• Inlet air measurement for engine testing

• HVAC testing

• Environmental monitoring in clean rooms

• Coating process monitoring – for confectionary
and pharmaceuticals

• Control of humidity for metallurgical processes

Chilled Mirror Instruments

Optidew
Chilled Mirror Hygrometer

The Optidew series is both robust and adaptable, designed
for dependable performance, whether it’s in a harsh industrial
environment or in a laboratory.

New design of chilled mirror sensor: fast
response speed with drift-free reliability

The Optidew uses a new design of cooled mirror sensor which
gives a fast response speed coupled with the accuracy and
reliability of the fundamental chilled mirror technique (see
opposite page).

Measuring in climatic chambers, the Optidew is able to
directly track changes in temperature and humidity without
experiencing time-consuming loss of control like traditional
chilled mirrors.

Touch-screen HMI for easy operation

Both the wall mounted and bench top models are available
with a 5.7” colour touch screen display to make local
operation and interrogation quick and simple to carry out.

Three housing confi gurations

Optidew 401:

A bench top instrument, the
Optidew 401 has a simple,
intuitive touch-screen HMI
which for easy confi guration and
operation. This version includes
a USB port and SD card slot for
easy data logging.

This chart shows a transition from a starting condition of
50%RH at 23°C to 25%RH at 50°C. The transition time shown
is purely that of the climatic chamber: no time is wasted
waiting for the Optidew to stabilise.

Ideal for use as an easily
transportable reference
hygrometer. Either as a transfer
standard to make fi eld calibrations of climatic chambers, or in
combination with a Michell HygroCal100 for validation of RH
probes.

The optional transport case allows use of the instrument
without even unpacking it – great for fi eld service work.

Optidew 501 – with display

The wall mounted Optidew
501 is designed for continuous
measurements of humidity
in industrial environments.
Modbus over RS485 is provided
as standard, with the option of
Modbus TCP over Ethernet for
simple networking of multiple
instruments.

A 316 Stainless steel sensor
block is available to connect the sensor to a fl owing sample. It
features an additional port so that a pressure transmitter can
be installed directly at the point of measurement.

Choice of sensors to suit different
applications

The dual-stage harsh environment sensor is designed for
tough industrial conditions and allows high temperature
measurements up to 120°C, for applications in metallurgy and
fuel cell testing.

The standard sensor is available with single- or dual-stage
cooling and is a reliable and cost-effective option for many
environmental control applications.

The optional pressure sensor gives additional detail about
the measurement. You can now clearly see whether changes
in dew point are related to moisture content or pressure. If
moisture content needs to be displayed in ppm
live pressure changes will be compensated for.

or g/kg, any

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The Optidew 501 has the same touch screen interface as the
bench mount version. Operators can easily interrogate and
confi gure the instrument locally or remotely via the application
software.

Optidew 501 – transmitter

The most cost effective option
is the wall mounted Optidew
501 blind transmitter. All the
features of the other models are
available when connected to a
PC and operated via Michell’s
universal software. The multi-color
LED indicator also displays the
instrument’s status.

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