Zero Cal; Auto Mode Zeroing - Teledyne 3000TA Operating Instructions Manual

4 Operation
Shut off the gas pressure before connecting it to the analyzer, and
be sure to limit the pressure to 40 psig or less when turning it back on.
Readjust the gas pressure into the analyzer until the flowrate (as read on
the analyzer's SLPM flowmeter) settles between 0.1 and 2.4 SLPM (ap-
proximately 0.2 - 5 SCFH).
If you are using password protection, you will need to enter your
password to gain access to either of these functions. Follow the instructions
in sections 4.3.3 to enter your password. Once you have gained clearance to
proceed, you can enter the Zero or Span function.

4.4.1 Zero Cal

The Zero button on the front panel is used to enter the zero calibration
function. Zero calibration can be performed in either the automatic or manual
mode. In the automatic mode, an internal algorithm compares consecutive
readings from the sensor to determine when the output is within the accept-
able range for zero. In the manual mode, the operator determines when the
reading is within the acceptable range for zero. Make sure the zero gas is
connected to the instrument. If you get a CELL FAILURE message skip to
section 4.4.1.3.
4.4.1.1
Press Zero to enter the zero function mode. The screen allows you to
select whether the zero calibration is to be performed automatically or manu-
ally. Use the Δ∇ arrow keys to toggle between AUTO and MAN zero
settling. Stop when AUTO appears, blinking, on the display.
Press Enter to begin zeroing.
The beginning zero level is shown in the upper left corner of the dis-
play. As the zero reading settles, the screen displays and updates information
on Slope (unless the Slope starts within the acceptable zero range and does
not need to settle further).
Then, and whenever Slope is less than 0.08 for at least 3 minutes,
instead of Slope you will see a countdown: 5 Left, 4 Left, and so fourth.
These are five steps in the zeroing process that the system must complete,
AFTER settling, before it can go back to Analyze.
4-12

Auto Mode Zeroing

Zero: Settling: AUTO
<ENT> To Begin
#### PPM Zero
Slope=####
Teledyne Analytical Instruments
ppm/s
Model 3000TA