Campbell Scientific Ltd., Campbell Park, 80 Hathern Road, Shepshed, Loughborough. LE129GX,UK

Tel: +44 (0) 1509 601141 Fax: +44 (0) 1509 601091 Email: sales@campbellsci.co.uk

www.campbellsci.co.uk

IRS21 Intelligent Road

Surface Sensor

Specifications

Lufft’s IRS21 is a passive

sensor that monitors road

surface temperature, freezing

temperature for NaCl (others on

request), road condition (dry/

damp/wet/ice or snow / residual

salt/freezing), and water film

level (up to 4 mm). This

intelligent road surface sensor

is a primary component of our

Road Weather Information

Stations (RWIS). When used in

an RWIS application, the IRS21

is connected to a CR800,

CR850 or CR1000 datalogger

via the SDM-SIO1 Serial Data

Interface Module.

Installation

Two IRS21 sensors are typically

installed at the measurement

site. Each sensor is placed

inside a hole in the road and

then the hole is fitted with epoxy.

To provide accurate

measurements and prevent

damage to the sensor, the

IRS21 must be installed flush to

the road surface.

CSL 547

May 2009

Operating Humidity:

100% RH

TemperatureRange:

-40° to +70°C

operating; -50° to +70°C

storage

PowerRequirements:9to14

Vdc; less than 200 mA (during

measurement)

Interface:RS-485

RoadConditionOutput:dry,

damp,wet,snow,freezing

wetness,ice

RoadTemperatureRange:

-40° to +70°C (-40° to +158°F)

RoadTemperatureAccuracy:

±0.2°C (-10° to 10°C);

±0.5°C (-40° to 70°C)

RoadTemperatureResolution:

-0.1°C

Freezing Point Range: -20° to

0°C (-4° to +32°F)

Freezing Point Accuracy:

±0.1°C

Freezing Point Resolution:

-0.1°C

Dimensions: 13 cm (5”),

diameter, 5 cm (2”) height

Weight: 0.9 kg (2 lb)

Ordering Information

IRS21 - Intelligent Road Surface

Sensor with 25 m (75ft) cable.

SDM-SIO1 - Serial Interface

Module