A manufacturer of headlight and taillight assemblies leak tests them for porosity, cracks
and seam integrity. A light assembly must be airtight to avoid contamination from
moisture or dust. The test stand operator needs a local display to indicate the flow rate.
Future development of the test stand will require an output signal for data acquisition.


50D-2-A2-G0 Thermal Mass FLO-METER
A-115VAC Power Adapter Package


McMillan Model 50D Thermal Mass FLO-METER has an integrated display and provides
an analog output signal which is proportional to the flow rate. The Power Adapter
Package includes a power supply, connection hub and cable assembly with pigtail
(soldered wire) ends.


Regulated air bypasses the Model 50D to fast fill and pressurize the light assembly. Next
the 3-way valve switches to the low flow channel. The display and/or the output signal
are closely monitored, if the flow rate exceeds 3 sccm the assembly is rejected due to


McMillan Company’s patented thermal mass design provides accurate repeatable results
with minimal zero drift. Metal construction, compact size and reasonable price make the
Model 50D an ideal choice for this customer’s needs. The integrated display pivots up to
45° allowing easy view of the flow rate by the operator. NIST-Traceable calibration and
recalibration service are available from McMillan Company. Custom versions are offered
to OEM customers.


Figure 1 illustrates the flow path of the fluid system and power adapter package.

FIGURE 1 – Flow Path of Fluid System and Power Adapter Package