Arizona Hydrogen Sulfide Analyzer Jerome 631-X - Manual (Page 45)

Fresh Air Solenoid
An external three-way solenoid can be used to provide fresh air or conditioned air during sensor
regeneration. This may be necessary if the sample stream lacks molecular oxygen. A low current
six volt DC solenoid, connected between pins 19 and 11 of the 25 pin rear panel connector, will be
energized during the regeneration cycle if the option board SW100 switch 6 is placed in the OFF
position.
If needed, the circuit may be built from the following components and configured as shown in the
following diagram. It will only function if the option board is installed in the 631-X instrument.
Required Parts:
Suggested Part Similar AZI P/N
1 solenoid, 6volt 3way Angar P/N 407569 1300 1004
1/8" to 1/16" tubing adaptor Any 1300 0025
1/2" clamp, adhesive mount Any 6000 0013
1/8" tube to instrument adaptor Any 1400 3010
3" 1/8" tubing Tygon Formula R3603 2500 3001
A/R 1/16" tubing Tygon Formula R3603 2500 3002
1 25 pin male DB-25 connector
Solder-cup style
AMP 747912-2 None *
1 connector hood AMP 749626-2 None *
* These are types not stocked by AZI, but should be available overnight from many AMP stocking
distributors such as Digi-Key Corporation. There are multiple suitable alternatives such as Radio
Shack’s 276-1547 and 276-1549.
TO SAMPLE
SOURCE
TO FRESH AIR
SOURCE
TO INSTRUMENT
1/8" TUBE
1/16" TUBE
1/16" TUBE
1/16" TUBE
PIN 1 PIN 1
REAR OF CONNECTOR,
CONNECT TO PINS 11 AND 19
MOST INSTRUMENTS
REAR OF CONNECTOR,
CONNECT TO PINS 19 AND 21
631-X SHIPPED IN 1994 ONLY
AZI Customer Service 800-528-7411 or 602-470-1414 Page 45 of 50