Product guide

55
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.
www.michell.com
Precision Manufacturing
Accessories and Spare Parts
RS422/485 to PC (RS232) converter 330185
USB cable/software for confi guration F035263
SS interchangeable probe with 2m (6.56') cable USTE015
SS cap slotted with mesh fi lter K1
SS cap slotted with PTFE fi lter Z1
You can check your hygrometer with the Control Kit HKC
which is based on the principle of non-saturated salt
solutions. Refer to technical data sheet CONTROL KIT
HKC
WR285
Digital Relative Humidity Transmitter - Remote Probe for Pressurized
Applications up to 30 bar (400 psi)
The WR285 relative humidity sensor uses the Hygrosmart
module, integrated in the interchangeable probe. This device
can be used in high-temperature applications due to the
remote measurement element and its small overall size. The
interchangeable probe allows for simple recalibration and
lower maintenance costs.
Highlights
• Up to 30 bar (400 psi) pressure
• Analog and digital output standard
• Interchangeable probe
• Analog output signals selectable through software
• Metric or US measurement units selectable through
software
• Can withstand temperatures up to 120°C (248°F)
Technical Specifi cations
Performance
Measurement range (RH) 0–100% RH
Accuracy at 25°C (77°F)
Humidity
<±2% RH (5–95% RH)
Stability – RH Sensor ±1% RH/year
Response time – RH Sensor <10 sec typical (for 90% of the step change)
Electrical output/input
Output signal 0–1, 0–5, 0–10 V
0–20 mA, 4–20 mA, RS485
Supply voltage 15 - 27 V AC / 18 - 38 V DC
Load resistance Current output: R  500 
Power consumption 1.7 W
Operating conditions
Operating temperature
Probe
Housing
Storage
-30 to +120°C (-22 to +248°F)
-30 to +70°C (-22 to +158°F)
-40 to +70°C (-40 to +158°F)
Mechanical specifi cation
Ingress protection IP67
Material
Housing
Probe
Aluminum die casting
Stainless steel
Dimensions
Housing
Probe
120 x 120 x 51mm (4.72 x 4.72 x 2.00”)
L=148mm, ø18mm (L=5.82”, ø0.70”)
Weight 450g (15.87oz)
Electrical connections Screw terminals
INTERCHANGEABLE
PROBE
HYGROSMART ®
Dimensions
Issue No: WR285_97193_V2_UK_1110