Product Overview
The QMA601 Moisture Analyzer is a high-performance process moisture analyzer designed to provide fast, reliable and accurate measurement of moisture content in a wide variety of carrier gases used in industrial processes. It uses advanced Quartz Crystal Microbalance (QCM) technology to achieve trace-level moisture measurement with very low detection limits, suitable for critical process control and quality assurance in hazardous area environments.
Technical Specifications :
- Measurement Range:1 to 2,000 ppm₍V₎ (wide dynamic range)
- Lower Detection Limit:1 ppm₍V₎
- Accuracy: ±0.1 ppm₍V₎ at <1 ppm₍V₎; 10 % of reading from 1 to 2,000 ppm₍V₎
- Repeatability: ±0.1 ppm₍V₎ (<1 ppm₍V₎), ±5 % of reading (1–2,000 ppm₍V₎)
- Response Speed: T₆₃ <2 min, T₉₅ <5 min to step change
- Units of Output: ppm₍V₎, ppm₍W₎, mg/Nm³, vapor pressure (Pa), dew point (°C/°F), lb/MMscf
- Calibration: Internal automatic calibration traceable to NPL & NIST
- Electrics: 85–264 V AC or 24 V DC (depending on certification)
- Digital Communications: RS485 Modbus RTU, Modbus TCP
- Display: 7” color LCD with intuitive HMI
- Approvals/Certifications: IECEx, ATEX, UKCA, TR CU Ex, cQPSus (explosion-proof)
- Maintenance: Typically maintenance-free for ~3 years
The analyzer features an intuitive touch screen HMI that can be used without a hot works permit and provides built-in process gas verification, selectable alarms, and predefined carrier gas settings.
Description
Measurement Technology
The QMA601 uses Quartz Crystal Microbalance (QCM) technology — a highly sensitive measurement principle in which a quartz crystal oscillator’s resonant frequency changes in response to tiny mass changes on its surface. In the QMA601, the crystal is coated with a hygroscopic layer that adsorbs water molecules from the process gas. As moisture accumulates on the crystal surface, the effective mass increases, producing a measurable frequency shift. The magnitude of this shift is directly proportional to the amount of moisture in the gas, allowing robust calculation of moisture content down to trace levels (0.1 ppm₍V₎).
This gravimetric measurement technique enables the QMA601 to maintain high accuracy, repeatability, and stability even under conditions where the carrier gas composition varies. Because the frequency change is fundamentally tied to mass loading, the QCM sensor is significantly less sensitive to environmental factors that can affect other sensing principles. The analyzer also includes internal automatic calibration using a built-in moisture generator, ensuring measurements remain traceable to national standards (NPL & NIST) and reducing drift over long operation cycles.
The QMA601 is engineered for industrial environments and certified for hazardous area operation across multiple global standards, making it suitable for processes involving natural gas, refinery applications, petrochemical carrier gases, and other process streams where precise moisture control is required. Minimal routine maintenance and a low cost of ownership are achieved through robust design and extended service intervals.
Technical Specifications:
- Measurement Range:1–2000 ppm₍V₎, calibrated range 0.1–700 ppm₍V₎ for standard cycle
- Limit of Detection:1 ppm₍V₎
- Sensitivity:01 ppm₍V₎ or 1 % of reading
- Analog Outputs: 2 × 4–20 mA or 1–5 V, selectable
- Alarms: System alarm plus 3 configurable process alarms
- Sample Flow: ~300 mL/min total
- Operating Conditions: Sample gas temp 0…+100 °C; analyzer internal +5…+45 °C (with appropriate enclosure adaptations)
- Enclosure: Explosion-proof cast aluminum with IP66/NEMA4 rating
- Mechanical: 1/8” NPT gas connection; ~35 kg (analyzer only)
Applications:
- Natural gas dehydration and transmission/ storage monitoring
- Refinery process recycle gas moisture control
- LNG production and vaporization dew-point checks
- Ethylene/propylene production moisture monitoring
- Carrier gas quality control in petrochemical processing
