Orbisphere 3600 series - Analog Outputs Description

22 3600 Analyzer for O
2
Measurement—Operator’s Manual
3600O2.OM.E9903
Under the “Modify Options” menu, highlight “Analog Output” using the arrow
keys, and then press “ENTER” to display this screen:
CUSTOM ANALG OUT
DISABLED ENABLED
Highlight “Enabled” and press “ENTER” to set your custom analog output levels.
ANALOG OUT 0000
LOW LEVEL ^
Use the “ñ” or “ò” arrow keys to increase or decrease the highlighted digits, and
then press “ENTER” to move to the next digit. First, set up all of the significant
digits without regard for the position of the decimal point or units. Once the fourth
digit is set, press “ENTER” to see the following screen:
AL = 43.21 ppm 3
UP/DOWN MODIFIES
In this menu, “AL” represents the Analog Low Level. The rightmost digit on the
top line indicates which range is affected: 1 refers to the lowest range, 2 to the
second range, and so on. Use “ñ” or “ò” to modify this setting, and then press
“ENTER” to save your selection.
The instrument then proceeds to the Analog High Level menus, similar to the two
above (in the last screen, “AH” is used as the abbreviation). After you enter the
high level, the instrument returns to the “Modify Options” menu.
1.4.4.1 Analog Outputs Description
Four analog outputs are available when the instrument is connected to an external
AC or DC power supply (but not available for battery power). The analog outputs
provide separate signals that represent the measured O
2
concentration,
temperature, pressure, and a range indication. These outputs are available as 0–5
Volts, 0–20 mA, or 4–20 mA. See section 2.1.4.4 for analog (recorder) output
wiring connections, and section 2.1.8.2 for current/voltage output conversion.
The analog outputs are generated using a 12-bit digital converter; thus, the
minimum increment of any output can be determined by dividing the output range
by 4096. For example: You could set the gas concentration range to 0–500 ppm for
4–20mA, and your recorder would still pick up changes of 0.2 ppm. The accuracy
of each increment is 1%.
O
2
concentration (gas) output
You can scale the analog output signal representing sample O
2
concentration
between any two gas concentration levels, “AL” and “AH” (see menus above).
The default values of these levels are 0 and 9999, respectively. When “Custom
Analog Output” is enabled (with the “Analog Output” menus above), the AL and
AH levels can be set as desired.
The relation between the analog output current “I” (in mA) or voltage “V”, and
the gas concentration “C” is as follows, as scaled by these limits:
0–20 mA C = AL + (AH - AL) * I/20
4–20 mA C = AL + (AH - AL) * (I - 4)/16
0–5 Volts C = AL + (AH - AL) * V/5