The Krefelder engineer's office ELK again supplements the portfolio of sensors of its multi-measuring instrument BAPPU. The device for the collection of health-relevant parameters on the job in the context of workplace analyses is extended by the measurement of carbon dioxide (CO2). Altogether BAPPU now offers 10 measuring sections:
Global temperature (Globe thermometer)
Noise (current and averaged)
Max. screen brightness
Refresh rates (on screens and other light sources)
A direct examination of the values conformity to legal demands is carried out by the confrontation of actual and required values (thresholds) and their assessment in plain language.
Because humans breathe out carbon dioxide the concentration of CO2 in the ambient air is considered as index for the air quality. Related to safety on the job this concerns office work in particular, because offices are frequently used by a high quantity of persons.
According to DIN 1946 for that reason hygenic maximum values in buildings with air conditioners may not exceed 0,15 percent by volume CO2 (this corresponds 1500 ppm). Depending on the number of persons and the intensity of the ventilation this limit value can be achieved fast in naturally ventilated areas (thus by windows and doors).
In a non ventilated classroom with 45 persons a value of 3000 ppm was measured already after 1 hour without being influenced by further burn processes (tobacco smoke, candles, cook devices…)!
In order to specify air quality regarding the percentage of CO2 an appropriate sensor for BAPPU was developed and implemented into the system. The sensor enables to determine the necessary number of ventilation intervals and/or the settings of air-conditioners. The sensor system is based on the so-called „non-dispersive infrared spectrometry “(NDIR), an established and accurate measuring procedure. The CO2-sensor is connected to the operating unit of the BAPPU-Globe-thermometer. Among current readings their development in the course of the last minutes is shown on the 4-lined-display in a graphical manner. As known from the basis equipment, the evaluations (value OK, tolerable, outside border) are indicated in order to indicate needs for action already locally. All values of the 99 internal store can be transmitted into an appropriate PC program under Vista or XP and to be further evaluated and documented.
The BAPPU CO2-signal-light, a further new development, allows the permanent and stationary monitoring of air quality in classrooms, lecture-rooms, office etc.