Land 4500 MKII Premier, Operation And Maintenance Manual

Page: 65 / 139

Model 4500 Premier Dust and Opacity Monitor
65
B3.2 Calibration Audit
A convenient Calibration Audit facility is provided, for carrying out the Calibration Audit tests required by
USEPA and other Environmental Regulatory Authorities.
Calibration Audit and Modbus Communications
When the instrument is in maintenance mode Modbus communications are disabled. It is therefore not
possible in this mode to monitor the results of the Calibration Audit and Response Time tests using the
Modbus.
If Modbus communications are required during a Calibration Audit, follow the instructions in Calibration
Audit Method 2.
Calibration Audit Method 1 (Modbus disabled)
1 Press and hold the Maintenance key unit the red LED illuminates (about 5 seconds).
2 Enter the password using the
↑
and
↓
keys, then press the ‘ENTER’ (
↵
) key. The default password
is 10.
3 Use the DOWN ARROW key to select Calibration and press ENTER.
4 Use the DOWN ARROW key to select CAL AUDIT and press ENTER.
5 The zero reflector is driven into its working position. The displayed value should be 0.00 ± 0.010.
Note that this is fractional Opacity, i.e. 100 % is shown as 1.00.
6 Open the transceiver housing by releasing two quick-release clamps, and swing the instrument
open on its hinges.
7 Insert a calibrated neutral density filter into slot 1.
1 Filter Slot
2 Zero Point Reflector
CAUTION
Do not attempt to move the zero point reflector (2).
The precision gearbox will be irreparably
damaged.
1
2