Michell Instruments QMA601 Specifications

Process Analyzers

QMA601

Process Moisture Analyzer

Fast, high-precision moisture measurements for hazardous areas.

The next generation Advanced Quartz Crystal Microbalance analyzer from Michell Instruments
is designed to provide reliable, fast and accurate measurement of trace moisture content in a
wide variety of process applications where keeping moisture levels as low as possible is of critical
importance.

Highlights

• Fast and reliable measurement from 0.1 to
2000ppm

• Accuracy of ±0.1ppmV at <1ppmV and 10% of
reading from 1 to 2000ppm

• Maintenance-free for 3 years

• Built-in verification of customer process gas

• IECEx, ATEX, TC-TR Ex certified for Exd flameproof,
CSA

• Intuitive, color HMI with touch-screen keypad; no
‘hot work’ permit required

• 14 internal alarms

• 21 predefined carrier gases and 3 user-defined
gases

• Proven Michell Instruments quality: 40 years of
expertise in moisture measurement built into the
design

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US certified for explosion proof

Applications

• Glycol dehydration of natural gas

• Molecular sieve dehydration of natural gas

• Natural Gas transmission and storage

• Refinery catalytic reforming — recycle gas
monitoring

• Ethylene and propylene production

• LNG production / revaporization

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Process Analyzers

40 Years of Experience with Moisture Measurement

The control of moisture is critical for the operational safety and efficiency of the plant equipment in upstream through to
downstream processes. We at Michell Instruments have been developing expert moisture-sensing instruments and systems for
40 years. Over this time, we have developed the world’s largest range of moisture and hydrocarbon dew-point analyzers for the
oil, natural gas, refining and power industries. We have gained extensive knowledge of applications in these industries, with
thousands of installations in sites across the globe.

Introducing the QMA601
Process Moisture Analyzer

Precision Measurement

• High accuracy with lower detection limit of 0.1 ppm

• Wide range of 0.1 to 2000ppm

• Sensitivity of 0.01ppm

The QMA601 is the result of Michell Instruments’ continuous
effort to improve Quartz Crystal Microbalance technology. The
new analyzer utilizes a new generation of precision crystal
oscillators guaranteeing a highly accurate measurement
which is completely insensitive to changes in background
gas composition.

While other moisture technologies are being stretched at
sub-ppm trace moisture levels, the new QMA601 can offer
reliability, simplicity and greatly reduced cost of ownership
from trusted and proven Quartz Crystal technology.

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Reliability

For maximum stability, all critical components of the QMA601
— the moisture generator, sensor and flow control devices
— are precisely temperature controlled. This ensures that
fluctuations in sample gas or environmental temperature
have no influence on the measurement.

The analyzer utilizes a mass flow controller to ensure precise
control of the sample and reference gas flows to ±0.1 ml/
min. Coupled with a pressure transducer, this system ensures
continued accuracy of measured and calculated parameters
even during fluctuations in sample pressure.

Simplicity

Human Machine Interface (HMI)

The QMA601 provides a highly intuitive, menu driven color
interface, utilizing a capacitive touch-screen keypad. This
powerful HMI makes control, logging and configuration of
analyzer parameters very simple. The main display also
incorporates real-time trend graphing and alarm indicators
based on the NAMUR 102 standard. This allows operation
and interrogation of the analyzer in the field with no need
for a ‘hot work’ permit.

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Easy Integration into Existing Control Systems

The QMA601 is equipped with two analog outputs,
configurable for either current or voltage scaling. It also
provides both Modbus RTU Protocol over RS485 and Modbus
TCP for easy connection to a SCADA or other user-defined
data acquisition system.

Dedicated remote application software is also available.

Integrated Sampling System

The instrument can be supplied with a high quality, in-house
designed, sample conditioning system that is optimized
for the application, as well as for the requirements of the
analyzer.

Reduced Cost of Ownership

Minimum Maintenance

Sophisticated instruments are often complicated and
require experience and special care in use, increasing
cost of ownership. The QMA601 differs through its very
uncomplicated approach to field service; the desiccant dryer
is easy to replace via its mounting on the sampling panel.
The moisture generator has an average life span of 3 years
before replacement is required. The analyzer will therefore
perform reliably for many years with just basic maintenance
and housekeeping.

Automated Verification

The QMA601 incorporates an automatic or manual
verification system that can use either the internal traceable
moisture generator or an external reference supplied by the
user. Carried out on the process gas flow, these periodic
validation-checks of sensor performance can be initiated on
demand, or automatically (at user-defined intervals and time
of day), providing a verification of analyzer performance
and automatically adjusting out any change. The moisture
generator at the core of the system is supplied with a
calibration traceable to NPL and NIST.

Ease of Installation

Available with a choice of either AC or DC powered versions.*
No barrier unit or safety earth are required, saving the user
both cost and inconvenience.

*CSAUS version 24V DC only

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