ENMET OMNI-4000 - Manual (Page 29)

OMNI-4000 S/N 6705 and above ENMET Corporation
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2.4.5 STEL and TWA
This information, programmed by the manufacturer and contained in the internal memory of the sensor and the
instrument, is available whenever at least one toxic sensor is connected and operational, and the instrument is ON:
•
The STEL data (Short Term Exposure Limit) for each toxic channel (STEL symbol, type of gas, reading and
unit of measurement) is displayed each time the MENU switch is pressed. Press it again to display the next
operational channel. The STEL values are only displayed after the device has been on for at least fifteen
minutes.
•
The TWA (Time Weighted Average) for each toxic channel (TWA symbol, type of gas, reading and unit of
measurement) is displayed each time the MENU switch is pressed. Press it again to display the next operational
channel. The TWA values are only displayed after the device has been on for at least two minutes.
Figure 2-15: Example of Display of the STEL
The procedure is identical to the Min/Max procedure.
2.4.6 Returning to the Operational Mode
This occurs immediately after the last information on the STEL/TWA values on an OMNI-4000 with at least one toxic
sensor installed, or after the min.-max. values for an OMNI-4000 with no toxic sensor installed.
Return to the instantaneous readings at any time can be obtained:
•
Immediately, by pressing the BACKLIGHT switch
•
Automatically after a 30 second delay
N OTE : Other displays are also available with this procedure. However, they can only be accessed after connection of a
printer or computer.
STEL CO 200 ppm
Measure: 22 ppm