Detcon PI-500 - Manual (Page 20)

3.7 S OFTWARE F LOW C HART
3.8 C ALIBRATION
Material Requirements
* Detcon PN 943-003270-000 MicroSafe™ Programming Magnet
* Detcon PN 943-000006-132 Calibration Adapter
* Zero Air gas containing no VOC compounds
* Span gas containing isobutylene in air. The cal gas concentration is recommended at 50% of range (which is the fac-
tory default) at a controlled f low rate of 200 cc/min. Example: for a Model PI-500 sensor with a range of 0-100ppm,
a test gas of 50 ppm isobutylene is recommended. For a sensor with a range of 0-10 ppm a test gas of 5 ppm is rec-
ommended, etc. Other concentrations can be used as long as they fall within 10% to 90% of range. See section
3.8.2 for details. Reference section 3.9-b-1 if you do not know the sensor target gas or range of detection.
3.8.1 Calibration Procedure - Zero
NOTE 1: Before performing a zero calibration, determine if there are any active VOC target gases in the area. If it can
be concluded that there are no active VOC gases in the area, then execute steps b) and c) below.
NOTE 2: Assuming that there are some residual VOC target gases in the background, you will require the use of the
zero air gas standard to perform a correct zero calibration starting from step a) below.
a) Apply a zero air standard at 200 cc/min for approximately 2-3 minutes then proceed through steps b) and c) with the
gas under continuous f low. After applying gas, place your f ingertip over the exit port of the cal adapter for 10 -30
seconds to expedite the gas purging process.
b) Enter the calibration menu by holding the programming magnet over PGM 1 (see Figure #6) for 3 seconds until the
display reads “1-ZERO 2-SPAN”, then withdraw the magnet. Note that the Cal LED should now be illuminated.
c) Next, enter the zero menu by holding the magnet stationary over “PGM 1” for 3 seconds until the display reads:
“Setting Zero”, then withdraw the magnet. The sensor has now entered the auto zero mode. When it is complete
the display will read “ZERO COMPLETE” for 5 seconds and then return to the normal operations menu reading.
PI-500 Toxic Gas Sensors PG.20
NORMAL
OPERATION
CALIBRATION
PGM1 (3) PGM2 (3)
1-ZERO 2-SPAN
LEGEND
PGM1 - program switch location #1
PGM2 - program switch location #2
(M) - momentary pass of magnet
(3) - 3 second hold of magnet
(30) - 30 second hold of magnet
INC - increase
DEC - decrease
# - numeric value
AUTO ZERO AUTO SPAN
GAS RANGE
PGM1 (3) PGM2 (M)
VIEW PROG STATUS
PGM1 (M) PGM2 (M)
PGM1 (3)
CalLevel @ ##PPM
INC DEC
PGM1 (3) PGM2 (M)
SET CAL LEVEL
PGM2 (3) PGM2 (3)
SENSOR LIFE ##%
PGM1 (3)
PGM2 (30)
CAL LEVEL @ ##PPM
PGM1 (M) PGM2 (M)
PGM1 (3)
RESPFACTOR = X.XX
INC DEC
PGM1 (3) PGM2 (M)
SET RESPONSE FACTOR
PGM2 (3)
PGM1 (M) PGM2 (M)
PGM1 (3)
ZERO OFFSET = X.X PPM
INC DEC
PGM1 (3) PGM2 (M)
SET ZERO OFFSET
PGM2 (3)
Software Version V#.#
ZERO OFFSET = X.XX
RAW SIGNAL = X.XX V
Figure 6
Figure 7