Carbon Monoxide Alarm User Manual

Page 29
Chapter 6 Record Keeping
6.1 PhD
2
datalogging overview
The PhD
2
automatically remembers (logs) gas readings,
as well as other important information such as turn-on /
turn-off times, temperature, battery condition, and
whenever the instrument is calibrated.
The PhD
2
can store the exposure values for up to 3,000
data intervals. This is enough for the storage of up to 50
hours of four gas monitoring broken into as many as 36
individual monitoring "sessions" when a one-minute
logging interval is specified. Using a longer datalogging
interval increases the length of monitoring time for which
data may be stored. For instance, if a data-logging
interval of two minutes is selected, instead of 50 hours,
100 hours of monitoring data may be stored.
This datalogging is a "transparent" function; that is, it is
not necessary to do anything special to begin logging
data. Simply turning on the instrument causes it to begin
recording data. This information may be downloaded to a
computer to create a permanent record, or directly
displayed on the PhD
2
meter screen.
Although it is not necessary to make use of information
being recorded and stored by the PhD
2
, it is there in the
event it is needed.
6.1.1 Optional Datalink and Gas Detection
Database Software kit
An optional Datalink and Gas Detection Database
software kit is available for use with the PhD
2
. The kit
allows your PhD
2
and your computer to communicate
with each other.
The software serves two basic functions: getting stored
information out of the instrument and into your computer,
and using files stored in your computer to setup or
"program" your PhD
2
.
It is important to note that it is not necessary to use the
Datalink software to program your PhD
2
. All
configuration and setup options may be programmed
directly by using the built-in buttons on the instrument
keypad.
On the other hand, the datalink software has been
designed to make programming, downloading, and data
analysis as easy as pushing a button. The software
allows optional instrument setups to be created by "filling
out" forms right on the computer screen.
Most functions (such as downloading stored information
from the instrument to your PC, or uploading
configuration setup files from your PC to the instrument)
are automatic. The software is designed to help you
along.
Once information has been "downloaded" to the
computer, it may be used for a variety of purposes. Data
may be displayed and reviewed in detail through the
computer monitor screen, or used to automatically
generate and print reports, tables and graphs of time
history exposure data. It is also possible to export
records to other software applications in the form of
ASCII, Lotus compatible, or "comma delimited" database
files. Another option is to simply retain downloaded
records of your gas detection monitoring program.
Note: The material in Chapter 6 is primarily designed
to acquaint our customers with the manual PhD
2
setup and download procedures. Full instruction for
use of the Datalink and Gas Detection Database kit
are contained in the PhD
2
Datalink manual. Please
consult these materials for further guidance.
6.2 Adjusting record keeping
parameters
It is possible to adjust or customize the way the PhD
2
logs data in a number of different ways. Options include
extended recording time, tagging the exposure data with
time and date information, or assigning a location
number.
6.2.1 Entering the Datalogging Adjust
mode
Turn on the PhD
2
while holding down the "+" button.
(The unit must be in the Technician mode prior to being
turned on.) The Datalog Adjust screen will briefly appear.
The Datalog Adjust screen is followed by the sample
interval adjust screen.
6.2.2 Adjusting the sampling interval
When the PhD
2
is turned on it immediately begins to
monitor, calculate, and log exposure levels for the
atmospheric hazards it is set up to detect.
For the purposes of developing a time history chart or
graph this continuous data stream must be broken into
discrete intervals before being logged. The sample
interval screen allows the user to adjust how frequently
this data is logged.
Calculations that are made on a running basis (i.e.
TWA, STEL, Ceilings, and Peak exposure values) are
updated several times per second by the PhD
2
microprocessor. Adjusting the sampling interval
used by the PhD
2
to generate time history exposure
files does not alter the way in which TWA, STEL,
Ceiling, and Peak exposure values are calculated.
The sampling interval may be set anywhere between one
second and one hour by using the "+" and "-" keys. The