envea STACK 710, User Manual

Page: 42 / 68

5 Periodic Mode of Operation STACK 710
42
(PC-000878-MA Issue 7, December 2021)
ENVEA UK Ltd
5.2.3 Exit from Audit Mode
Use the and arrows to select Stop and press .
The Zero Reflector is retracted, and the instrument resumes normal operation.
Press twice to return to the main screen.
5.3 Clear Stack Calibration
A Clear Stack Calibration must only be performed when there is no smoke or dust
in the beam of the opacity monitor. It can be carried out in-situ if a clear optical
path can be achieved. Alternatively, the instrument may be removed and attached
to test stands or a pipe for calibration. The STACK 710 provides a convenient
facility for testing on a workbench or other flat surfaces. The Transceiver may be
laid on its left side and the Retro-reflector on its right side; the screw on the left
side of the Transceiver case can be adjusted to achieve the correct alignment.
Note that unless the calibration is performed in-situ, the distance between the
Transceiver and the Retro-reflector must be adjusted until it exactly matches the
distance in normal operation ± mm (1/4”).
Ensure that the pathlength is correct and that the surfaces of the main lens and
Retro-reflector’s elements are clean and dust-free. Align the instrument as
described in B 1-4 paragraph .
Press
Unlock is displayed, press
Use the and arrows until the Supervisor code (Default: 10) is displayed
and press .
Use the and arrows to select Calibration and press .
Use the and arrows to select Clear Stack Calibration and
press Start is displayed. When ready, press .
Confirm Clear Path is displayed. Check that the optical path is clear and press
the hourglass is displayed while the instrument waits for the readings to
settle.
Confirm Blocked Path is displayed. The simplest way to achieve a blocked
path is to release the clips on the side of the Transceiver and swing it open on its
hinges until the beam is pointing into free space. Alternatively, to calibrate the