RHB-1500-Series

Supported Applications

The Omega RHB-1500 Series is a portable chilled mirror dew point monitor designed for primary field measurement of Dew/Frost Point. The instrument integrates microprocessor control with self-balancing functionality to provide NIST-traceable accuracy in transportable configurations. It serves as a complete, self-contained system requiring no field assembly.

Documented media compatibility includes air and inert gases suitable for clean, non-corrosive gas applications. The series is configured for use in pressurized systems up to 150 psig; units require an external pump when deployed with non-pressurized systems.

Operating Conditions & Performance

The RHB-1500 Series operates within an ambient temperature range of 0 to 50°C (32 to 122°F). Measurement capabilities vary by stage configuration:

• 2-Stage (S2): -40 to 50°C (-40 to 122°F)
• 3-Stage (S3): -60 to 50°C (-76 to 122°F)
• Dew/Frost Point Range: -60 to 75°C (-76 to 167°F) with an accuracy of ±0.25°C (0.45°F).

The instrument features a sample flow rate capability of 0.5 to 5 SCFH via an integral flowmeter and accepts inlet pressures from 0 to 150 psig, with higher pressure options available upon consultation. The unit is housed in a plastic carrying case measuring 37.5 H x 46 W x 18 cm D (14.75 x 18 x 7") and weighs 11 kg (24 lb).

Configuration Options

The series offers configurable power, sensor stage, probe location, and accessory options to address specific field requirements.

• Power Supply: Models are available with rechargeable batteries for portable operation (nominal 12-hour battery life) or line-powered configurations accepting 115 to 230 Vac at 50 to 60 Hz. Line-powered models include a built-in charger.
• Sensor Configuration: Options include standard chilled mirror sensors and remote chill mirror probes (e.g., Model RHB-1500-C1DS2R).
• Analog Output: 4 to 20 mA or 0 to 5 Vdc with a compliance of 9.0 Vdc into 450 Ω load resistance.
• Display & Alarms: Features an eight-digit, alphanumeric red LED display (0.5" tall). Alarm functionality includes programmable set points with visual flashing "ALARM" messages and one Form C non-latching relay contact rated at 10 A @ 240 Vac or 8 A @ 24 Vdc.
• Process Connection: Standard connection is a ¼" compression fitting. Sample tubing options include copper, stainless steel, or plastic (1/4").
• Accessories: Available configurations may include an ambient temperature probe with a 3 m (10') cable and a replacement PR-11-3-100-1/4-6-E-120 temperature probe.

Key Product Differences

The RHB-1500 Series distinguishes models by power source, chill mirror stage count, and sensor placement. Battery-powered variants (e.g., C1) provide field portability with rechargeable cells, while line-powered variants (e.g., C2 or L suffixes) operate directly from 115/230 Vac mains.

Stage configuration defines the low-temperature limit: S2 models cover -40 to 50°C (-40 to 122°F), whereas S3 models extend down to -60°C. Remote sensor options (indicated by "D" in model codes such as RHB-C2-DS2) separate the chilled mirror element from the main unit, allowing for flexible installation geometries.

Additional suffixes denote included accessories; for example, variants ending in "RHB-ATP" include an ambient temperature probe with a 3 m (10') cable. The series includes standard features such as Programmable Automatic Balance Control (ABC) and comes complete with an operator's manual, SCFH air flow controller, and NIST certificate.