Comet System Web Sensor T5540, Руководство пользователя

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IE-SNC-T5(6)5xx-08
4
Introduction
This chapter provides basic information about device. Before starting please read
this manual carefully.
The Web Sensor devices are designed for measurement of temperature, relative humidity
and carbon dioxide concentration of air without aggressive substances. Measured quantities
are according device type. Devices with relative humidity measurement can show one of
computed quantities: dew point temperature, absolute humidity, specific humidity, mixing
ratio and specific enthalpy. Temperature units are °C or °F. Communication interface of
Web Sensors is Ethernet. Device types:
Type Temperature Relative humidity CO
2
concentration Computed quantity
T5540 
T5541 
T5545 
T6540    
T6541    
T6545    
Models marked TxxxxZ are custom-specified devices. Description of these devices is not
included in this manual.
A multiple point CO
2
and temperature adjustment procedure leads to excellent CO
2
measurement accuracy over the entire temperature working range; this is a must for process
control and outdoor applications. The dual wavelength NDIR CO
2
sensing procedure
compensates automatically for ageing effects. The CO
2
module is highly resistant to pollution
and offers maintenance free operation and outstanding long term stability.
Measured values can be read in „SLOW mode“ (filtered, averaged) or in „FAST mode“
(current values without averaging). „SLOW mode“ has advantages in applications like
climate control because of filtering short time peaks. As an example exhaled air from an
employee passing the sensor could affect the climate control negatively with a short response
time because the control would trigger a change of the ventilation based on this one-time
measurement. On the contrary in „FAST mode“ no software filter is used for calculating the
output value. This fact adds a noise of typ. ±30ppm which has to be considered in terms of
accuracy. Of principle measurement is the measured value of CO
2
concentration depends on
the value of air pressure - altitude at the installation site. For this reason, it is suitable for
accurate measurement to set the altitude of the installation site.
After power up of the device starts internal test. During this time (about 20s) LCD display
shows (----) instead of CO
2
concentration value. Web pages show n/a.
Chapter
1