Hach Ultra MET ONE 227, User Manual

Page: 16 / 59

15
Section 4 Operation
4.1 Power up
Use the power switch at the bottom of the counter to turn on the MET ONE 227 particle
counter (refer to
Figure 5 on page 13 , item 3). When first turned on, the counter will
display the main screen ( Figure 6 on page 16 ). The MET ONE 227 particle counter
exhibits various counting modes. The factory default setting for the counting mode will be
the Manual mode.
4.2 Factory default settings
Table 1 lists the default parameters that are programmed at the factory. Refer to Section
4 on page 15 for a detailed explanation of the terms and instructions required for
programming parameters.
4.3 Manual mode
In the Manual mode, the MET ONE 227 particle counter takes one sample of
programmed length (default is one minute) and stops. This operation is based on the
factory default settings described in
Table 1 on page 13 .
To initiate a 1-minute count cycle:
1. Press
1
on the front panel (refer to Figure 6 ). The pump will begin to operate. The
count cycle status will change from “Stop” to “Wait” for two seconds while the pump
reaches maximum speed.
The count cycle status (refer to Figure 6 , item 2) will change to “Run” during the
1-minute sample and return to “Stop” at the end of the count cycle. The MET ONE 227
particle counter draws 0.1 cubic foot of air through the instrument. Multiply the results
by ten to calculate the particle counts per cubic foot.
Table 1 Default parameter settings
Parameter Setting
Location number 000
Count mode Manual (the counter will take one sample and stop counting)
Alarm limits 0 (no particle count level alarms will be registered)
Channel 2 particle size 0.7 micron in 227A; 0.5 micron in 227B
Volume Liters (applies to Concentration mode only)
Temperature °C (only if RH/T probe is attached).
RS232 mode Normal
Baud rate 9600
Sample time 1 minute (length of sample period)
Hold time 1 second (hold time between samples in Automatic mode)
Program mode Unlocked (allows user programming).