Bacharach PCA 2 24-9448 - Manual (Page 90)

Instruction 24-9448 6-10
Maintenance
6.5 Nitric Oxide Sensor Battery Replacement
A sngle lthum battery, located on the NO Smart Sensor assembly, apples
a bas voltage to the NO sensor to prevent the sensor from destablzng
when the analyzer s turned off. The NO bas battery s expected to last at
least the lfe of the NO sensor.
Note: It is recommended that the bias battery be replaced whenever the NO
sensor is replaced.
Material Required:
• Bas battery (refer to Secton 8.1 Replacement Parts)
Procedure:
1. Follow the nstructons n Secton 6.3 Smart Sensor Replacement to
remove the Smart Sensor assembly from poston 4.
2. Remove the old battery from ts holder on the Ntrc Oxde prnted
crcut board.
3. Insert the new battery wth the postve sde facng away from the
sensor (the battery contact s stamped wth a + symbol) .
4. Re-nstall the Smart Sensor assembly.
5. Before powerng up and usng the analyzer, allow the Ntrc Oxde
sensor to stablze as descrbed below. Note that recalbraton of the
Ntrc Oxde sensor s not requred after replacng ts bas battery.
Dependng on how long the Ntrc Oxde sensor was wthout bas
voltage, the tme requred for the sensor to completely stablze vares
from less than a mnute to several days. Typcal stablzaton tmes
are shown below. Generally, however, the sensor s suffcently stable
after 4 hours for measurement purposes.
Bias battery removed for . . . Stabilization time
Less than 15 mnutes Less than 1 mnute
Less than 1 hour Less than 5 mnutes
Less than 2 days Less than 4 hours
Greater than 2 days Up to 2 days