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

The Model 973 Dew Point Mirror is a portable instrument equipped with an integral measuring head for both spot and continuous measurement of Dew/Frost point and temperature in air and gas mixtures.

Based on the chilled mirror principle, the 973 ensures direct and accurate humidity measurement.

Chilled mirror condensation technology provides highly precise, stable and repeatable results.

• Highly precise chilled mirror dew point technology
• Cable mounted dew point and temperature measurement
• Aspirated and direct insertion measuring heads
• Barometric pressure measurement options
• Intuitive color touch screen user interface
• User verifiable calibration

Water vapor condenses onto a temperature controlled mirror surface and this ‘dew point’ is detected with advanced optical electronics. Since dew point is specific to water vapor concentration and not temperature dependent, measurement precision is consistent across the full application range including high temperature and humidity conditions in climatic test chambers.

MBW chilled mirror hygrometers have a typical service life of more than 15 years thanks to the use of high quality materials and Swiss precision engineering. The high quality platinum resistance thermometer (PRT) element embedded within the mirror ensures excellent long term measurement stability. Thanks to the precise dew point and temperature measurements as well as the stability and long service life, MBW chilled mirrors are used by national standards and accredited laboratories worldwide. The 473 transfers reference standard performance into applications such as climatic chamber validation, relative humidity calibrators and a wide range of industrial processes.

The RH Systems CGS-240 Humidity Generator is a system capable of continuous, high-accuracy humidity generation over a wide range of humidity, temperature, and flow rates.

The G2 produces highly accurate humidity values, delivering a humidified gas stream, accurately controlled to a variety of user-selectable humidity parameters such as %RH, dew point, frost point, ppm, or vapor pressure.

By accurately measuring the temperature and pressure at the point where the humidified gas is utilized, the G2 automatically adjusts for changes in dynamic conditions such as heat load or ambient pressure variation.With RH Systems’ hybrid humidity generation technique, the G2 is a true humidity reference instrument suitable for high accuracy calibration, product conditioning, and test applications.

High Flow Capability

With flow rate capacity up to 100 standard litres per minute, the G2 ensures your external volume or test chamber rapidly achieves a stable, homogeneous humidity condition based on your defined RH or dew point setting.

Embedded System For Control

Operations are automated with real-time, embedded control systems. Its setpoints are commanded and data is retrieved via robust serial communications. There are three fully capable, yet fully independent RS-232 serial ports, allowing for a variety of communication options.

Multiple External Temp Connections

By splitting the high-flow gas stream and feeding into three separate chambers, with each chamber controlled at a different temperature, three unique %RH values will be produced. The G2 computes the resulting %RH at each of these three chambers based on the three external temperature measurements.

The Model G9 produces highly accurate humidity values based on the NIST proven “two-pressure” humidity generation technique.

This system will generate a variety of humidity values such as %RH, dew point, frost point, ppm, or vapor pressure. The system is computer controlled, allowing it to run at fixed points, or multipoint profiles, completely unattended.

Use of the vacuum chamber eliminates atmospheric water vapor permeation and the need for thermal insulation materials in and around thermally controlled components.

Additionally, Stirling cryo-coolers (more accurately Free-Piston Stirling Coolers) are used to cool the saturator.
With these improvements over conventional designs, the G3 has better accuracy and performance at low humidity due to reduced permeation effects, improved thermal insulation and control, faster cool down characteristics, and better maintenance access.

Key Features

Precision Meets Innovation – The G3 Frost Point Generator isn’t just another humidity tool—it’s a leap forward in ppb level calibration and testing. By combining vacuum-sealed insulation with dual Stirling cryocoolers, it eliminates the permeation and thermal transfer issues that plague conventional frost point generator systems.

Ultra-Low Range

Frost/Dew Point from -120°C to +10°C – Perfect for applications demanding extreme dryness, like semiconductor manufacturing or aerospace testing.

1. Vacuum-Insulated Saturator – Unlike traditional insulation, the G3’s vacuum chamber actively removes water vapor, ensuring no permeation and unmatched thermal stability.
2. Dual CFC-Free Cryocoolers – Cuts cooldown time in half, or more, so you spend less time waiting and more time testing.
3. Three Independent Flow-Controlled Outputs – Need multiple test streams? The G3 delivers three precise, adjustable flows up to 10 slpm total, all from a single unit.
4. Hybrid Two-Temperature, Two-Pressure Principle – A NIST-proven method for absolute accuracy, even at the lowest humidity levels.

The PT12 is a highly precise and stable platinum resistance thermometer (PRT) based multi-channel temperature measurement system.

Using a custom designed high-quality measurement circuit with full current reversal and multiplexed sampling, the PT12 provides 12 channels of low uncertainty temperature data for validation and calibration engineers.

• Twelve channel temperature measurement
• High precision, stability and repeatability
• Internal temperature compensated high stability reference resistors
• PC software for easy GUI or command line system control and data acquisition
• Simple to setup, configure and use
• Touchscreen user interface with graphing
• Supports THERMOtelligent^TM 100 Ω and 25.5 Ω Smart 4-wire PRTs