Product guide

69
Humidity and Dew-Point Instruments
Please note: Michell Instruments adopts a continuous development program which sometimes
necessitates specifi cation changes without notice. Please contact us for latest version.
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Calibration
OptiCal
Relative Humidity and Temperature Generator with built-in Chilled Mirror
Reference
The OptiCal is a bench-top, fully self-contained humidity/
temperature calibrator. The system comprises a humidity
and temperature controlled chamber that can house up
to fi ve or more humidity sensors, depending on their
physical dimensions. The humidity and temperature within
the chamber are closed-loop controlled and continuously
monitored by a precision chilled mirror reference hygrometer.
The OptiCal works by time-proportioning the fl ows of dry and
saturated air according to the pre-selected relative humidity
value. The chamber temperature is controlled by a four-zone
Peltier heat pump arrangement for maximum stability and
minimum temperature gradient. The saturator assembly
can be fi lled easily with the distilled water reservoir at the
front of the unit and the easily accessible desiccator can be
re-charged by heating when required. No other maintenance
is necessary. The only external service required is a single
phase power supply.
Highlights
• Precision relative humidity and temperature calibrator
• Generate 10 to 90% RH over +10 to +50°C (+50 to
+122°F) temperature
• Integral chilled mirror reference hygrometer
• UKAS Accredited Calibration, as standard
• Humidity and temperature profi le generation for
unattended verifi cation of sensors
• Transportable to allow on-site calibrations
Technical Specifi cations
Reference Hygrometer
Type Optidew chilled mirror dew-point
transmitter
Humidity
Generator range 10–90% RH
Accuracy
Control element
±1% RH (10–70% RH)
±1.5% RH (70–90% RH)
Stability ±0.2% RH (20–80% RH)
Temperature
Generator range +10 to +50°C (+50 to +122°F)
(lowest T set point = 10ºC (18°F) below
ambient)
Accuracy ±0.1°C (±0.2°F)
Stability ±0.1°C (±0.2°F)
Chamber
Ramp rate from
+20 to +40°C (+68 to +104°F)
+40 to +20°C (+104 to +68°F)
1.5°C / minute (2.7°F / minute)
0.7°C / minute (1.2°F / minute)
Control element Removable relative humidity sensor
General
Probe ports up to 5 – sensor body diameters 5–25mm
(0.2 to 0.98”) accommodated by port
adapters
Chamber volume 2000 cm
3
(122.1in
3
)
Chamber dimensions 105 x 105 x 160mm (4.13 x 4.13 x 6.3”)
(wxhxd)
Instrument dimensions 520 x 290 x 420mm (20.5 x 11.4 x 16.5”)
(wxhxd)
Set point resolution 0.1 for humidity and temperature
Displays High defi nition 2 lines alpha numeric
Measurement units ºC, ºCdp, % RH
g/kg, g/m
3
, (t-t
d
), a
w
Outputs
Analog
Digital
Alarm
Two channels 4-20 mA or 0-20 mA
RS232 (RS485 optional)
Volt free contact, 2A @ 30 V DC
Supply 85–264 V AC, 47–63 Hz, 150 VA
Weight 20kg (44lb)
Logging and profi ling software
Issue No: OptiCal_97161_V3_UK_0811