3RBM-Series

Supported Applications

The Weiss 3" Rear Connect Bimetal Thermometer with Recalibrator (3RBM Series) is a stainless steel, hermetically sealed bimetal thermometer designed for industrial temperature monitoring. The series overview explicitly identifies applications in process equipment, petrochemical facilities, oil & gas operations, pulp & paper mills, wastewater treatment systems, and food processing environments.

Operating Conditions & Performance

The 3RBM Series measures temperatures from -80°F (-40°C) through 1000°F (537°C), with specific range codes defining the scale limits. Accuracy is rated at ±1.0% of full range, conforming to ASME B40.200 (B40.3 Grade A). The ambient operating temperature spans -40-250°F (-40-120°C).

Performance characteristics include a silicone-dampened bimetallic element that maximizes response time. Standard stem lengths are available up to 12" (including thread), with a probe diameter of 0.250". The series utilizes wetted materials constructed from 300 series stainless steel for both the stem and connection.

Installation notes specify that Weiss bimetal thermometers should always be installed in a thermowell in pressurized applications to protect the stem from erosion and corrosion, allowing removal without disturbing the process. For continuous service up to 800°F (425°C), standard configurations are satisfactory; intermittent service is supported up to 1000°F.

Configuration Options

The series offers configurable dimensions and options tailored to specific installation requirements:

• Housing & Dial: Features a 3" dial housed in 304 stainless steel, hermetically sealed. An external recalibrator is standard.
• Process Connection: Rear connect angle form with 1/2 NPT threading constructed from 300 series stainless steel.
• Stem Lengths: Standard lengths include 2.5", 4", 6", 9", and 12" (including thread). Longer stem lengths are available as an option.
• Dial Options: Available configurations include single scale ranges (°F Only Scale, °C Only Scale), a polycarbonate window, or a silicone liquid filled case.

The model number guide follows the format: 3RBM - <Stem Length> - <Range Code>. Standard range codes cover intervals from -80/120°F to 2000/1000°F, with specific graduation markings defined per code.

Key Product Differences

Variants within the 3RBM Series are distinguished by stem length and temperature range. Standard models include:

• Stem Lengths: Models such as 3RBM25 (2.5"), 3RBM4 (4"), 3RBM6 (6"), 3RBM9 (9"), and 3RBM12 (12") correspond to the stem length in inches.
• Range Codes: Suffixes like -120, -250, -800, or -1000 denote specific temperature ranges. For example, code "-120" covers -80/120°F & -60/50°C, while "-1000" covers 2000/1000°F (note: source text lists this range as 2000/1000°F in the table row for code 1000†).

Specific constraints apply to certain ranges: a minimum stem length of 4" is required for specific codes marked with an asterisk (*). The series supports thermowells as accessories, requiring consultation of the Weiss Thermowell Data Sheet for specifications and selection.