Duet
Duet Chilled Mirror Hygrometer
A perfect harmony of Dew and Frost point measurement.
The Duet from RH Systems is a state-of-the-art chilled mirror hygrometer developed and manufactured in the United States. Independently designed by Bob Hardy, RH Systems founder, the Duet blends traditional chilled mirror technology with modern enhancements to create a highly precise, portable standard for dual Dew and Frost Point measurement along with PPM and relative humidity.
Dual Measurement Mastery
Optimizing the chilled mirror principle, the Duet’s precision engineering and advanced measurement algorithms deliver accurate, direct humidity measurements, including dew point, frost point, %RH, ppm, ambient temperature, and pressure.
Precision & Portability
Ratiometric resistance measurement with dual embedded thermometer. Weighs 20-25 lbs with custom Pelican case for on-site measurement.
Harmonious Dew-Frost Discrimination
FrostLock establishes a known condensate state –either frost or super-cooled dew — at mirror temperatures below 0°C, eliminating mixed or ambiguous conditions. This harmonious precision in dew-frost discrimination resolves long-standing industry misconceptions, ensuring accurate calculation of dependent humidity values.
Design Based On Fundamental NIST Developed Principles
A system capable of continuous, high-accuracy humidity generation over a wide range of humidity, temperature, and flow rates.
Reliability and Performance
Optimizing the chilled mirror principle, the Duet’s precision engineering and advanced measurement algorithms deliver accurate, direct humidity measurements, including dew point, frost point, %RH, ppm, ambient temperature and pressure.
Dew-Frost Differentiation
FrostLock ensures a known condensate state – either frost or super-cooled dew – at mirror temperatures below 0 °C, eliminating mixed or ambiguous conditions. This harmonious precision in dew-frost detection resolves longstanding industry misconceptions, ensuring accurate calculation of dependent humidity values.
ARIA - Accelerated Response Injection Algorithm
ARIA minimizes the time required for low frost-point measurement by rapidly depositing a controlled condensate layer on the mirror, ensuring sufficient thickness for reliable frost-point detection.
Dual Mirror PRTs
The Duet is equipped with two independent, 100 ohm, 4-wire, mirror PRTs for precise mirror temperature measurement. The second PRT enables direct temperature monitoring using your own resistance bridge or our optional PT12 Precision Thermometer.
Verifiable Calibration
Using the known 0 °C ice-melt temperature, the built-in IceTest function instantly confirms system accuracy and integrity.
Robust Connectivity
Versatile communication interfaces include RS-232, TCP/IP and USB. Use the included RHS Control software for real-time control and data acquisition, or develop custom software using our straightforward, fully documented command protocol.
Feature Complete
Every Duet comes fully equipped with an integrated pump, flow meter, pressure sensor and external temperature probe, ready for immediate operation.
| MODEL | DUET | DUET-HT |
|---|---|---|
| Measuring Range | ||
| Frost / Dew Point | -60 ºC FP to 20 ºC DP | -40 ºC FP to 70ºC DP |
| Relative Humidity | 0.1 %RH to 100 %RH |
|
| Temperature | -100 ºC to 100 ºC * (calibrated range -20ºC to 70ºC) |
|
| Accuracy | ||
| Frost / Dew Point | ± 0.1°C |
|
| Temperature | ± 0.07°C |
|
| Reproducibility | ||
| Frost / Dew Point | ± 0.05°C |
|
| Temperature | ± 0.05°C |
|
| Inputs / Outputs | ||
| Digital Communication | RS-232, USB-B, TCP / IP |
|
| Analog Outputs | 2 Channel, 0-5 V or 0-20 mA (user configurable) |
|
| 2nd Mirror PRT | Pt100, 4-wire connection |
|
| Measurement and Display | ||
| Mirror Cooling | 3-stage Thermoelectric |
|
| Measuring Head Cooling | Air |
|
| Display | Color Touch Screen |
|
| Gas Couplings | 1/4" or 6 mm Swagelok (specify) |
|
| Sample Gas Flow Rate | 0.2 l/min to 2 l/min |
|
| Sample Gas Circuit | PFA | Heated, Stainless Steel |
| Sample Gas Max Pressure | 2 bara |
|
| Environmental | ||
| Operation Temperature | 10 °C to 30 °C |
|
| Storage Temperature | -20 °C to 60 °C |
|
| Ambient Humidity | ≤90 %RH, non-condensing |
|
| Power Requirements | ||
| Voltage | 100-240 VAC, 50/60 Hz |
|
| Power Consumption | 200 W | 300 W |
| Physical | ||
| Height | 155 mm |
|
| Width | 440 mm |
|
| Depth | 410 mm |
|
| Weight | 12 kg |
|
* Calibrated range -20 °C to 70 °C
