Portable Model XPDM
Hand-held, Battery Operated
The Portable Dewpoint Meter Model XPDM is a battery operated, hand-held instrument designed for situations where quick and accurate dewpoint measurements have to be made. With the XPDM, accurate spot-checks of moisture in air or gases can be made faster and easier than ever, over the range of -148°F to +68°F (-100°C to +20°C) dewpoint.		 Sample Cell Design
All surfaces in contact with the sample are made from 316 stainless steel and are electropolished to assure rapid equilibrium with the sample. Sensor and piston slide through spring-loaded PTFE seals protecting the sample cell as well as the desiccant cartridge from intrusion of wet air or gas.

The sample cell can measure gas flows up to 20 liters per minute. The flow rate has no effect on the measurement. The pressure in the sample cell is near atmospheric and should not exceed 2 bar (29 psi)

The instrument computer gives read out at any sensor pressure as well as at any line pressure the user enters for the particular sample. No correction is needed for different gases.
Operating Principle
Aluminum oxide sensors adsorb much faster than they desorb water molecules. It is an advantage, if at the beginning of the measurement. the sensor is dryer than the sample to be measured. The XPDM keeps the sensor in dry storage until the measurement is taken. The sensor slides directly from the dry storage into the sample cell, without ever coming in contact with ambient air. After the measurement is completed, the sensor slides back into the dry storage, where it is dried down for the next sample.

XPDM
Portable Dewpoint Meter

Technical Specifications - Model XPDM
Dewpoint Sensor Element
Type: Hyper Thin Film high capacitance AL2O3
Dew point range -148°F to +68°F (-100°C to +20°C)
Accuracy: ±5.5°F (± 3°C )
Repeatability: ±0.9°F (±0.5°C)
Response time*:
For a step change
from -40°C to -60°C;		 63% in 90 seconds; 90% in 450 seconds
Temperature range: Sensor: -22°F to 120°F (-30°C to +50°C)
Electronics: 14°F to 120°F (-10°C to +50°C)
Storage temperature: -4°F to +140°F (-20°C to +60°C)
Sample Flow range: Static to 100 m/s(linear velocity @1atm)
Calibration method: Automatic calibration, sensor saturates at dew points above +68°F (+20°C). NIST traceable factory calibration optionally available.
Temperature and Pressure Measurements: The sample temperature is measured with a precision integrated circuit temperature sensor. Units may be optionally fitted with a pressure sensor.

Mechanical :
Enclosure Anodized Aluminum, Dimensions: 2.5“ x 4.25” x 7.5”. Regulator and Filter mounting facilities.
Sampling Chamber: Electro-polished 316 stainless steel.
Moving Parts Seals: Spring energized PTFE seals.
Pressure operating range: Standard: 28 PSI (2 bar).Absolute max.: 100 PSI (6.9 bar)
Gas sample connections: 1/4” VCO input and output ports.
Electrical connections: Optional 2mm DC power jack, 9 pin “D” for analog & RS-232.
Power Requirements: 9v battery and optional 15-25V AC or DC wall transformer.

Features:
Sensor Storage: When not in use the sensor is retracted in a molecular sieve container and kept at an approximate dewpoint of -80°C. The sample gas pressure activates a piston which automatically moves the sensor into the sampling chamber, thus low dewpoints can be measured extremely quickly.
Input Resolution: 0.1°C dew point.
Indicators: LCD with backlight, 3.5 digits and custom legends for units and mode, audio alert.
Engineering Units: °C,°F, PPM, lbs.H2O/mm scf, gm.H20/m3
Controls: 5 push buttons, all settings stored in EEprom. Manual Sensor Actuator.
Outputs: Optional 4/20mA or 0/24mA and RS-232.
Isolation: Sensor and case are isolated from the power supply, analog output and RS-232.
Battery saver: Auto power off after 6 minutes.
Pressure Correct: Programmable pressure correction button.

* These response times are not directly comparable to competitors data because of differences in measurement methodology and data presentation. Please inquire for detailed comparisons between Xentaur and other major sensor manufacturers.
Product Overwiew
   Dewpoint Sensors     
Standard Dewpoint Transmitters
      Loop–powered     Dewpoint Transmitters
     Portable Dewpoint Instruments
Hazardous Area Products   
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Mission Critical Moisture Analyzer
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OEM Programs
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Calibration/Certification Services
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Combustion Calorimeter
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