Teledyne gfc 7000ta operation manual Auto Range Mode Auto

Operating Instructions Model GFC7000TA Carbon Dioxide Analyzer

6.8.5. Auto Range Mode (AUTO)

In AUTO range mode, the analyzer automatically switches the reporting range between two user-defined ranges (low and high). The unit will switch from low range to high range when the CO2 concentration exceeds 98% of the low range span. The unit will return from high range back to low range once both the CO2 concentration falls below 75% of the low range span.

In AUTO Range mode the instrument reports the same data in the same range on both the A1 and A2 outputs and automatically switches both outputs between ranges as described above. Also, the RANGE test function displayed on the front panel will automatically switch to show which range is in effect.

The high/low range status is also reported through the external, digital status outputs (Section 6.15.1.1).

To set individual ranges press the following keystroke sequence.

SAMPLE*	RANGE = 500.000 PPM	CO2 =X.XXX
< TST TST > CAL		SETUP

SETUP X.X	PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE		EXIT
SETUP X.X	RANGE CONTROL MENU
MODE SET UNIT		EXIT
SETUP X.X	RANGE MODE: SNGL
SNGL DUAL AUTO		ENTR EXIT

SETUP X.X			RANGE MODE: AUTO
SNGL DUAL AUTO						ENTR EXIT
SETUP X.X			RANGE CONTROL MENU
MODE SET UNIT						EXIT
SETUP X.X			LOW RANGE: 500.0 Conc
0	0	5	0	0	.0	ENTR EXIT
SETUP X.X			HIGH RANGE: 500.0 Conc
0	0	5	0	0	.0	ENTR EXIT

EXIT x 2 returns

to the main

SAMPLE display

Toggle the numeral buttons to set the LOW and HIGH range value. ENTR accepts the new setting, EXIT ignores the new setting.

CAUTION

In AUTO range mode the LOW and HIGH ranges have separate slopes and offsets

for computing CO2 concentration.

The two ranges must be independently calibrated.

NOTE

Avoid accidentally setting the low range of the instrument with a higher span limit than the high range. This will cause the unit to stay in the low reporting range perpetually and defeat the function of the AUTO range mode.

Teledyne Analytical Instruments 94