ATI
Model F12/D Gas Transmitter
Part 4
– Operation
42
O&M Manual (Rev-H)
Sensor Span Calibration
Span calibration* requires a bottled “span-gas” with a 500 cc/min regulator, calibration adapter, and a
convenient length of ¼” tubing. The gas type and concentration used depends on the type of sensor
installed. Check with the factory if you are uncertain about which gas to use.
Referring to Figure 50, slip the calibration adapter onto the exposed end of the sensor and connect one
end of
the tubing (1), connect the other end of tubing to the cylinder’s regulator (2). Do not open the gas
valve until instructed below.
* Perform the Zero calibration prior
to the Span calibration
.
Select the Span method from the
Sensor Calibration menu, as shown
in Figure 50
7
. This will clear and
inhibit alarms at the transmitter, and
hold the current loop output at 4mA
(17.4mA for Oxygen sensors) for up
to 30 minutes of no key activity.
Figure 50 Sensor Span Cal. Setup
Open the regulator and allow gas to flow to the
sensor. The displayed reading should begin to
increase and stabilize after 5 to 10 minutes,
depending on the gas type and range of the
sensor.
Select Span, the concentration reading will become fixed, and the blinking
Up/Dn edit cursor will appear just to the left of the reading. Press the
Up
or
Down
key to correct the reading to match the known concentration of gas.
Press the
Enter
key to perform the calibration. “Cal” will appear briefly at the
bottom of the page.
Figure 51. Sensor Span Cal. Menus
Press the
Esc
key twice to return to the Main page. Disconnect the calibration adapter from the sensor
and permit the readings to return to zero. Alarms will remain inhibited and the current loop will be fixed
for 30 minutes after calibration. Once the reading is below any of the alarm set levels, you may terminate
the alarm inhibit (and fixed loop output) using the
Esc
key on the Main Display, see
Inhibiting Alarms from the Main Display on page 35.
7
The span method is also directly accessible from the main menu.
1
2
Calibration
Zero History
►Span
Temp= 21.1°C
…Setup >Sensor>Calibration
PPM
H2S
►span
…Calibration>Span
0.0
PPM
H2S
►Span
24.8
…Calibration>Span
PPM
H2S
►Span
Cal
25.0
…Calibration>Span
