Direct Mount Temperature Gauge with Adjustable Limit Switch for Compressor & Engine Protection

This direct mount temperature gauge with adjustable limit switch provides accurate monitoring of compressor and engine temperatures in demanding industrial environments. The integrated adjustable trip point allows automatic alarm activation or equipment shutdown to prevent overheating and system damage. Designed for gas compressors, exhaust systems, and critical engine protection applications, it offers reliable performance across temperature ranges up to 1000°F.

100–1000°F Temp Range

±3% Accuracy

285psi Max Pressure

CSA Explosion-Proof

Key Features Section

Direct Mount Installation: Designed for direct process connection, this temperature gauge mounts directly into the equipment, eliminating the need for remote sensing assemblies and reducing installation complexity.
Integrated Adjustable Limit Switch: The built-in adjustable trip mechanism allows operators to set a specific temperature limit for automatic alarm activation or equipment shutdown, enhancing system protection.
Bi-Metal Mechanical Sensing Element: Utilizes a high-torque bi-metal element to provide reliable temperature indication without requiring external power, making it suitable for remote and hazardous environments.
Wide Temperature Measurement Range: Available in multiple configurations covering temperature ranges from 100°F up to 1000°F, supporting both standard and high-temperature industrial applications.
Dual Scale Dial Display: Clearly marked temperature scale in both Fahrenheit and Celsius ensures easy readability for international operations.
Rugged Industrial Construction: Built with stainless steel sensing components and durable housing materials to withstand harsh compressor, engine, and oil & gas operating conditions.
Explosion-Proof Model Available: Suitable for hazardous area installations where additional protection and compliance are required.

Applications

Gas Compressor Cylinder Discharge Monitoring: Helps prevent overheating by providing real-time temperature indication and activating protective shutdown when preset limits are exceeded.
Engine Exhaust Temperature Monitoring: Detects abnormal operating conditions such as overloading or improper fuel mixture in industrial and marine engines.
Oil & Gas Processing Systems: Suitable for temperature monitoring in pressurized and high-temperature process environments.
Marine Engine Protection Systems: Used in propulsion and auxiliary engines to maintain safe operating temperature and prevent component damage.
Industrial Engine and Generator Sets: Provides temperature supervision and automatic trip functionality for critical power generation systems.
Twin-Engine Load Coordination: Assists in balancing operating conditions between parallel engine installations.

Technical Specifications

Direct-mount temperature gauges with adjustable limit switch, designed for accurate monitoring and reliable shutdown protection in gas compressors, engine exhaust systems, and industrial applications.

Category	Details
Product Type	Direct-mount temperature gauge with adjustable limit switch
Temperature Ranges	SDB500 / SDB500EX / SDB501: 100° to 500°F (40° to 260°C) SDB1000: 200° to 1000°F (100° to 500°C)
Sensing Element	High-torque bi-metal element with stainless steel sensing bulb
Sensing Bulb	304 stainless steel, 1/2 in diameter × 4 in insertion depth (13 × 102 mm)
Maximum Bulb Pressure	285 psi (1.97 MPa) at 625°F (329°C); thermowell recommended
Process Connection	1/2 NPTF standard, 3/4 NPT adapter available
Contact Rating	SDB500 / SDB501 / SDB1000: 2 A @ 30 VAC SDB500EX: 2 A @ 120 VAC
Limit Contact Adjustment	Front knob adjustable across full temperature range
Maximum Unit Temperature	SDB500 / SDB500EX / SDB501: 625°F (329°C) SDB1000: 1250°F (677°C)
Case Material	SDB501: Die-cast aluminum SDB500 / SDB1000 / SDB500EX: Sand-cast aluminum
Accuracy	±3% of full scale (calibrated for thermowell use)
Dial	Stainless steel dial with black print, dual scale (°F and °C)
Wiring	18 AWG (1.0 mm²) lead wires
Certifications	CSA-listed explosion-proof model available (SDB500EX)
Applications	Gas compressors Engine exhaust temperature monitoring Load balancing in twin-engine systems
Shipping Weight	SDB501: 0.57 kg SDB500 / SDB1000: 1.0 kg SDB500EX: 1.05 kg
Shipping Dimensions	SDB501: 210 × 108 × 114 mm SDB500 / SDB1000: 210 × 108 × 114 mm SDB500EX: 229 × 140 × 152 mm

How the Direct Mount Temperature Gauge Works

The direct mount temperature gauge operates using a bi-metal mechanical sensing element housed within a stainless steel sensing bulb. When installed directly into the process connection, the bulb is exposed to the operating temperature of the compressor, engine, or exhaust system.

As temperature increases, the bi-metal element expands and converts thermal movement into rotational motion. This movement drives the dial pointer, providing accurate real-time temperature indication without requiring any external power supply.

The adjustable limit switch is set using the front-mounted control knob. When the pointer reaches the preset temperature limit, the internal switch activates, completing an alarm or shutdown circuit depending on system configuration.

By combining mechanical temperature indication with integrated protective switching, this device delivers both monitoring and automatic equipment protection in a single compact instrument.

Technical FAQ

Common Questions Answered

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A direct mount temperature gauge is installed directly into the process connection, allowing real-time temperature measurement without remote capillary assemblies or external transmitters.

The adjustable limit switch allows operators to set a specific temperature threshold. When the preset temperature is reached, the internal switch activates an alarm or shutdown circuit to protect equipment from overheating.

No. The temperature indication operates mechanically using a bi-metal sensing element and does not require external power. Power is only required if the limit switch is connected to an alarm or shutdown system.

It is widely used in gas compressor cylinder discharge monitoring, engine exhaust temperature monitoring, oil & gas processing systems, and marine engine protection applications.

A thermowell is recommended in high-pressure applications to protect the sensing bulb and allow safe removal of the instrument for maintenance without depressurizing the system.