Ametek 3050-DO

PN 305725901, Rev YF
Overview
The 3050 Moisture Analyzer is a smart sensor that measures trace concentra-
tions of moisture in a process gas stream. At the heart of the 3050-DO Analyzer
is a 3050-OLV, which has been modied for operation at moisture concentra-
tions below 100 PPBV. The 3050-DO Analyzer is compatible with He, Ar, Ne, Xe,
Kr, O
2
, H
2
, N
2
, NO, CO, CO
2
, light hydrocarbons, natural gas, refrigerants, air, and
specialty gases. Refer to Figure 1-4 for a Gas List. The analyzer is calibrated to
measure moisture content from 1–2500 PPMV. Data output can be in units of
PPMV, PPMW, lb/mmscf, and mg/Nm
3
.
The heart of the 3050-DO Analyzer is a quartz crystal microbalance (QCM) Sen-
sor that is sensitive to moisture. The QCM Moisture Sensor is simply a quartz
crystal oscillator, in which the quartz crystal has been coated with a propri-
etary hygroscopic coating. This coating selectively, and reversibly, absorbs
moisture from a Sample gas stream. As the crystal is exposed to a gas stream
containing water vapor, the hygroscopic coating absorbs moisture from the
gas stream, changing the mass of the coating. Changes in the mass are detect-
ed as changes in the natural resonance frequency of the oscillator.
In the analyzer’s Normal operating mode, the QCM Sensor is alternately
exposed to the Sample gas and a dry Reference gas. A dry Reference gas is
produced by passing a portion of the Sample gas through a dryer to remove
any moisture present (i.e., the moisture content of the dry Reference is less
than 0.010 PPMV). The dierence in the resonant frequency of the QCM Sensor,
as measured when exposed to each of the two gas streams, is a function of the
moisture content of the Sample gas. Thus, the moisture concentration of the
Sample gas is determined from this frequency dierence. The calibration data,
which relates the moisture concentration of the gas stream to the measured
frequency dierence, are stored in an EEPROM within the QCM Sensor module.
Figure 1-1.
3050-DO Analyzer.
Overview | 1-1