2 checking status remotely, 3 on-site system checks, Checking status remotely – Campbell Scientific AP200 CO2/H2O Atmospheric Profile System User Manual

Page 51: On-site system checks

AP200 CO

O Atmospheric Profile System

valve_number: this is normally an integer from 1 to 8, indicating which

profile level is being sampled. If the sequence is active, this number should

increment approximately every 15 s (see Appendix F, Valve Sequence Timing,

for details). It may be 9 (Zero) or 10 (CO

Span) if the zero/span sequence is

running. The corresponding LED on the valve module should be ON.

sample_flow: The expected value for the sample flow depends on the

elevation (see FIGURE 4-19 and FIGURE 4-20 for details). A significantly

higher flow indicates there may be a leak, whereas a significantly lower flow

indicates the filter or orifice may be plugged.

cell_press: This should be within ± 2 kPa of the pressure setpoint. See

Section 4.2.3, Pump Module, for details.

To access other tables in the CR1000, press

to go back to the top menu

and then select

System Menu. This gives access to all of the system tables. In

particular, the status table is helpful for assessing the status of the CR1000

datalogger (see the CR1000 User Manual for details), and the public table

shows the value of each public variable as it updates in real time. See

Appendix C, Public Variables, for details on the variables in the Public Table.

5.6.2 Checking Status Remotely

If the system is configured with an NL115 and a network connection is

available, the AP200 can be checked remotely by connecting a PC via

LoggerNet (other software is also available that provides some of the

functionality of LoggerNet – see Section 4.1.5, Support Software). LoggerNet

may also be used on-site with a serial cable connected directly to the

datalogger. All of the variables listed in the on-site access can be checked in

the Public table. For thorough performance verification, each of the variables

in the public table can be compared to their normal values. See Appendix C,

Public Variables, for details.

5.6.3 On-site System Checks

There are several important checks that can be done on site, during initial

installation, and during routine site visits to retrieve data and maintain the

system.

NL115 or CFM100: Check that the status LED is blinking red periodically,

indicating that data are being written to the card. See the NL115 or CFM100

manual for details.

Sample pump: Listen to the sample pump which should be making a steady

hum. A slight change in pitch is normal when switching between the

calibration (zero/span) and profile sequences, but a sustained oscillation in the

pitch indicates a problem. See Appendix B, AP200 Diagnostics, Bit 4.

Enclosure humidity: Check the humidity indicator card on the door of the

AP200 system enclosure and replace the desiccant when the humidity reaches

50%. See Section 7.2, Enclosure Desiccant.

Zero and span cylinders: Check the cylinder and regulator outlet pressures.

It is recommended to log the tank pressures at each site visit and note the trend.