Heath Consultants Hi Flow Sampler - Manual (Page 50)

Maintenance Hi Flow

Sampler
50 Instruction 0055-9017
4.7 Flow Rate Verification
This procedure verifies the Hi Flow  blower is operating at proper capacity and the flow
rate measurement is accurate. Use a calibrated flow rate meter or anemometer with a
minimum accuracy of +/-5%.
IMPORTANT: To assure accurate flow readings, conduct the following procedure in clean
air, free of any combustible gases.
1. Install the flow meter onto the Hi Flow  Sampler’s gas intake (see Figure 4-7).
2. Place the Hi Flow  Sampler into its Manual 1-Stage Mode per Section 2.14.2.2. Then
start the blower by selecting Start from the Main Screen.
3. The Flow (cfm) value as displayed on the Hi Flow  Sampler's LCD should be within
+/-5% of the measured cfm taking into account the flow meter's measurement
error and any pressure or temperature corrections.
Figure 4-7. Flow Meter Installation
4. With a fully charged battery pack, the measured flow rate should be greater than
9 cfm. If not, perform the following (see Figures 4-8 and 4-9):
• Clean the gas sample inlet screen.
• Ensure that the exhaust port is not obstructed.
• Remove the unit’s cover and ensure that the high- and low-sampling point hoses
are properly connected between the flow-measurement tube and their
corresponding solenoid valves, and that these hoses are not pinched or kinked.
• Ensure that no obstruction is present inside the flow-measurement tube.
• If none of the above solves the problem, return the unit to your nearest
Bacharach Service Center for evaluation.