CM4 Four-Point Continuous Monitor
CM4 Technical Manual
4-2
4.1 Introduction
This section describes:
• Monitor Mode (Section 4.2)
• Program Mode (
)
• Alarms and Faults (
• Accessing Programming Functions (
• CM4 Menu Structure (
• Keypad Locking Feature (
)
If you are not working with a CM4 as you read these sections, refer
to the illustrations in
4.2 Monitor Mode
Monitor Mode is the CM4’s standard operation state. After the instrument
is powered, the pump turns on and the instrument takes initial zero
readings and turns on the sample flow valve. The instrument:
• Continuously monitors gas concentrations at all four points
connected to the CM4
• Measures and calculates gas concentrations every second for
each of the four points
Response time is determined by the gas type and the alarm level
setting. The display shows the first reading:
PT 1 0 PPB AsH
3
The display continues to show the concentration monitored at each
point for a user-specified number of seconds, with a four-second
default:
PT 2 0 PPB AsH3
PT 3 0 PPB AsH3
PT 2 0 PPB AsH3
A fifth status line will be displayed, if applicable.
The concentration information for each point may be sent to three
optional outputs:
• Isolated current loop (4-20 mA)
• Serial
• Printer
NOTE:
Any time power is lost to the CM4, it enters Monitor Mode
automatically after power is restored.
When switching On Model CM4-P, the instrument requires up to ten
minutes for the pyrolyzer to heat up to its operating temperature. The
following display appears momentarily:
MONITOR MODE
The display then reads:
WARMING UP 600 SEC
Warm-up time is typically faster than initially indicated on the display
above. The Model CM4-P will usually begin monitoring approximately
one minute after <MONITOR> is pressed.
During the warm-up cycle, the display status LEDs will be flashing
green. The Chemcassette advances as the instrument enters analysis.
The display reads:
CURRENTLY MONITORING
During monitoring, the status LEDs for each active point will be solid
green. When the first concentration has been calculated, the display
will read:
PT1 NF3 = 0 PPM
珠海司福斯特科技有限公司
www.safedtech.com