AEROCET 831 Manual Rev A
Page 14
6.2.
Service Schedule
Table 2 shows the recommended service schedule for the AEROCET 831.
Table 2, Service Schedule
Item To Service
Frequency
Done By
Flow rate test
Monthly
Customer
Zero test
Optional
Customer or Factory Service
Calibrate Sensor
Yearly
Factory service only
6.2.1. Flow Rate Test
The sample flow rate is factory set to 0.1 CFM (2.83 LPM). Continued use and ambient
temperature/pressure variations may cause minor changes in flow which can reduce
measurement accuracy. A flow calibration kit is available separately that includes
everything needed to test/adjust the flow rate. To test the flow rate:
Remove the inlet screen holder
Connect the flow meter with inlet adapter (PN 80530) to the instrument inlet
Start a sample
Observe the flow meter reading after approximately 30 seconds
The flow rate should be 0.1 CFM (2.83 LPM) 5%
If the flow is not within this tolerance, it can be adjusted using a trim pot located in an
access hole in the side of the unit. Turn the adjustment pot clockwise to increase the
flow and counter-clockwise to decrease the flow.
6.2.2. Zero Count Test
The AEROCET 831 automatically monitors system noise and displays a System Noise
warning when the noise level is high (see Section 3.5.1). This diagnostic reduces the
necessity for an inlet filter zero count test. However, a zero count kit (PN 80846) can be
purchased separately if desired.
6.2.3. Annual Calibration
The AEROCET 831 should be sent back to Met One Instruments yearly for calibration
and inspection. Particle counter calibration requires specialized equipment and
training. The Met One Instruments calibration facility uses industry accepted methods
such as ISO and JIS.
In addition to calibration, the annual calibration includes the following preventative
maintenance items to reduce unexpected failures:
Inspect the exhaust filter
Caution:
The provided battery charger is designed to work safely with this device. Do
not attempt to connect any other charger or adapter to this device. Doing so
may result in equipment damage.
