5VBM-Series

Supported Applications

The Weiss 5" Dial Vari-Angle® Bimetal Thermometer (Series 5VBM) is a hermetically sealed bimetal thermometer designed for industrial process applications. The series features an adjustable vari-angle connection to accommodate various viewing angles during installation.

According to the manufacturer, thermowells must be used whenever this instrument is installed on pressurized applications or where pressure, high velocity, or corrosive media are present. This configuration protects the stem from erosion and corrosion while allowing for removal of the thermometer without disturbing the process.

Operating Conditions & Performance

The 5VBM Series provides temperature measurement ranges spanning -80°F to 1000°F (-40°C to 537°C). Accuracy is specified as ±1.0% of full range, meeting ASME B40.200 (B40.3 Grade A) standards.

• Process Temperature: -80°F to 1000°F (-40°C to 537°C)
• Ambient Operating Temperature: -40°F to 250°F (-40°C to 120°C)

The response time is maximized by silicone dampening within the bimetallic element. For continuous service, satisfactory operation extends up to 800°F; intermittent service can be performed up to 1000°F.

Temperature Limits and Warnings

No bimetal thermometer should be exposed continuously to process temperatures over 800°F (425°C). The temperature of the case must not exceed 200°F (95°C); for liquid-filled models, this limit is reduced to 150°F (65°C) to prevent dial discoloration or window failure.

Configuration Options

The series offers configurable stem lengths and range options. Standard stem lengths include up to 12" (including thread), with specific model codes denoting the length: 2.5", 4", 6", 9", or 12".

Construction Materials

• Housing Material: 304 stainless steel
• Process Connection: 300 series stainless steel, 1/2 NPT
• Wetted Parts (Stem and Connection): 300 series stainless steel
• Bimetallic Element Dampening: Silicone

The stem diameter is specified as 0.250".

Dial Ranges and Graduations

Standard ranges are available with dual scales (°F/°C) or single scale options. The following standard range codes define the measurement envelope:

• 120-LT: -80/120°F & -60/50°C
• 130*: 30/130°F & 0/55°C (Minimum stem length is 4")
• 200, 250: Ranges up to 250°F with corresponding °C scales
• 800*: 100/800°F & 40/425°C (Minimum stem length is 4")
• 1000†: 200/1000°F & 100/540°C (Intermittent service up to 1000°F)

Options and accessories include longer stem lengths, silicone liquid-filled cases, polycarbonate windows, single scale ranges (°F only or °C only), and thermowells.

Key Product Differences

The 5VBM Series is distinguished by its vari-angle connection design. Model numbers follow the format 5VBM - [Stem Length Code] - [Range Code]. For example, model 5VBM6-130 indicates a 6" stem with range code 130.

• SF Prefix: Models prefixed with "SF" (e.g., SF5VBM4-200) denote the silicone liquid-filled case option.

Installation requires mounting so that at least two inches of the free end of the stem are subjected to the average temperature. The thermometer should not be tightened by turning the case assembly; instead, use an open-end wrench on the hexagonal head of the threaded connection until reasonably tight, then adjust further for scale positioning.