2
Y99AB-4 BASO Test Kit Application Note
General Instructions
When using the test kit, insert the plugs securely
and squarely into the jacks. The thermocouple
adapters and nuts must be clean and tight. Any
meter fluctuation caused by the movement of these
parts may be due to loose connections. Poor
connections cause false readings. Three “D” size
batteries are required.
!
WARNING: Risk of Fire or Explosion.
In order to test the thermocouple under actual
flame conditions, it is necessary to hold the BASO
power unit open with the DC power pack provided
with the test kit. This eliminates the safety function
provided by the BASO power unit. Care must be
exercised during this test to ensure that gas is not
permitted to flow to the main burner.
!
CAUTION: Risk of Equipment Damage.
This meter is designed and calibrated for
Direct Current (DC) voltages up to 1000 millivolts
only. Any attempt to measure Alternating Current
(AC) voltage or DC voltage over 1000 millivolts will
damage the meter.
Open Circuit Millivolt Readings
Refer to Figure 8 through Figure 10 for typical
thermocouple-operated gas valve,
electrically-operated gas valve, and safety shutoff
device connection diagrams.
Perform the following procedure for taking open
circuit millivolt readings.
1. Shut off the gas supply at the main manual
shutoff valve.
2. Disconnect the thermocouple from the BASO
control.
3. Attach the test cable lead 44549-8 to the
thermocouple. Connect the red clip to the
copper tubing of the thermocouple and the black
clip to the terminal at the end of the
thermocouple (see Figure 2).
4. Set the slide switch on the meter to the 0-50 or
0-1000 position.
5. Re-establish
pilot
flame.
6. The millivolt reading should agree with the
values listed in Table 1 with a normal pilot flame
(see Figure 3).
Note: When taking an open circuit millivolt reading on
a junction block thermocouple, the junction block
terminal must be shorted (see Figure 4). This will isolate
the thermocouple from the high limit.
DC MILLIVOTS
PENN -BASO C ONT ROLS
0
10
20
30
40
50
100
300
500
700
900
MILLIAMPS
0-500
MILLIVOLTS
0-1000 0-50
ADJUST
MILLIVOLTS
MILLIAMPS
44549-8
Black
Red
Thermocouple
Lead
Figure 2: Open Circuit Millivolt Reading Connection
Diagram
Approximately
12.7 mm (1/2 in.)
Figure 3: Normal Pilot Flame
High
Limit
Switch
Shorting Wire
Figure 4: Junction Block Thermocouple
