Industrial Temperature Gauges

20T or 25T Mechanical Temperature Gauges

The 20T and 25T Mechanical Temperature Gauges are durable and precise instruments designed for reliable temperature measurement in various industrial applications. Featuring a mechanical design, these gauges operate without the need for external power, using a direct sensing mechanism to provide accurate temperature readings. The 20T and 25T models are known for their robust construction and clear, easy-to-read displays, making them suitable for monitoring temperatures in machinery, processing systems, and other demanding environments. Their dependable performance ensures effective temperature management and contributes to the safe and efficient operation of industrial systems.

The 20T and 25T Mechanical Temperature Gauges are analog instruments used to measure temperature in various systems, including industrial, automotive, and mechanical applications. These temperature gauges function using a mechanical sensor and display system, which is commonly based on the bimetallic strip or gas-filled capsule technology.

The 20T and 25T Mechanical Temperature Gauges are reliable, rugged, and straightforward instruments for measuring temperature in a wide variety of applications. Whether you're monitoring engine temperatures in an automotive setting, controlling temperatures in an industrial environment, or measuring heat in laboratory systems, these gauges offer a durable, accurate solution. They are particularly well-suited for applications where electrical sensors may not be viable and where simplicity, low maintenance, and cost-effectiveness are valued.

Industrial Mechanical Temperature Gauges (20T / 25T)

The 20 Series (2 inch/51 mm dial) and the 25 Series (2-1/2 inch/64 mm dial) Swichgage models are diaphragm-actuated, temperature-indicating gages with built-in electrical switches for tripping alarms and/or shut-down devices.

Ranges are available from 32°-120°F (0°-45°C) through 300°-440°F (160°-220°C).

The gage mechanism is enclosed in a steel case coated to resist corrosion. A polycarbonate, break- resistant lens and a polished, stainless steel bezel help protect this rugged, built-to-last instrument.

These vapor-actuated gages feature a sealed capillary tube and a sensing bulb. When subjected to heat, the liquid in the sensing bulb changes to vapor creating pressure against the diaphragm mechanism. The diaphragm translates this vapor pressure into a mechanical gage reading.

For series 20T and 25T, the gage pointer acts as a temperature indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contact(s) are grounded through the Swichgage case. They have a self-cleaning motion to enhance electrical continuity.

These instruments are used on equipment in oil field and monitoring engine coolant, crankcase oil and transmission oil.

Base Models

Coolant or Oil Tempature

Combination Indicating Gage and Limit Switch
Critical/High Temperature Limit Switch Is Visible and Adjustable (Most Models)
Switch Can Activate Alarms and/or Shut Down Equipment
Contact Grounds Through Case

Key Features of 20T and 25T Mechanical Temperature Gauges:

1. Mechanical Operation:

Bimetallic Technology: In many mechanical temperature gauges like the 20T or 25T series, temperature is measured via a bimetallic strip. This strip consists of two metals with different expansion coefficients, which cause the strip to bend when subjected to temperature changes. The movement of the strip drives a pointer on the dial to indicate the temperature.

Alternatively, some models may use a gas-filled capsule (such as a gas thermometer) that expands and contracts with temperature changes, driving the needle.

2. Temperature Range:

20T and 25T Series typically offer a variety of temperature ranges depending on the application, from as low as -30°C (-22°F) to +1200°C (2192°F) or higher for specialized models.

Common ranges may include -40°C to +120°C (-40°F to 248°F) for automotive or industrial use, and -100°C to +500°C (-148°F to 932°F) for higher temperature applications.

The precise range depends on the intended use—industrial, automotive, or laboratory settings.

3. Dial Size and Display:

These gauges generally feature dial sizes ranging from 2 inches (50mm) to 4.5 inches (115mm) in diameter. Larger dials are often preferred in industrial applications for easy readability from a distance.

The dial face typically displays the temperature scale in Celsius (°C) and/or Fahrenheit (°F). Some models may also feature a color-coded scale (green, yellow, red) for easy identification of safe, caution, or danger temperature ranges.

4. Accuracy:

Mechanical temperature gauges like the 20T or 25T Series are generally quite accurate, typically offering +/- 2% of full-scale accuracy. The exact accuracy can depend on the manufacturer and the specific model.

These gauges are designed for environments where high accuracy is important, but they might require periodic calibration to ensure long-term precision.

5. Durability and Construction:

These gauges are typically made with stainless steel or brass housings to ensure corrosion resistance in harsh environments. The sensing elements (bimetallic strips or gas capsules) are often made from high-quality metals or alloys to ensure accurate readings and long service life.

The crystal on the face of the gauge is commonly made from glass or plastic, depending on the model and intended use. Some gauges are liquid-filled, which helps dampen the needle movement, providing smoother readings and better resistance to vibration.

6. Mounting Options:

Mechanical temperature gauges often offer several mounting options, such as back mount, front mount, and panel mount, depending on the application requirements.

This flexibility makes the 20T and 25T series suitable for various applications, from automotive engine monitoring to industrial heating systems.

7. Sensor Length:

The temperature-sensing probe or capillary tube of mechanical temperature gauges in the 20T and 25T series varies in length. Longer sensors are used in applications where the measurement needs to be taken from a distance or from within a confined space, such as in engine bays or industrial machines.

Common Applications:

1. Automotive:

Used to monitor engine temperatures such as coolant temperature, oil temperature, or exhaust gas temperature. The 20T or 25T gauges are particularly useful in performance vehicles or racing environments where precise, real-time monitoring is crucial for engine health.

2. Industrial Applications:

Mechanical temperature gauges are frequently employed in industrial machinery, boilers, pressurized systems, and HVAC systems. They are well-suited for environments where temperature control is critical, and where electrical components might be vulnerable to damage from high temperatures or harsh conditions.

3. HVAC (Heating, Ventilation, and Air Conditioning):

They are used to monitor temperatures in air ducts, compressors, refrigeration systems, and cooling towers to ensure that systems operate within optimal temperature ranges.

4. Laboratories and Research:

In laboratory settings, mechanical temperature gauges can be used to measure temperatures in chemical reactions, furnaces, ovens, and other experimental setups, where accurate and real-time temperature readings are required.

5. Food and Beverage:

The food processing industry uses these gauges to monitor cooking, pasteurization, and storage temperatures to ensure proper food safety and quality control.

Advantages of 20T or 25T Mechanical Temperature Gauges:

No Power Required: Mechanical temperature gauges do not require electricity to function, making them ideal for environments where electrical power is unreliable or unavailable.

Durability: These gauges are built to withstand harsh conditions, including vibration, temperature extremes, and corrosive environments. This makes them ideal for heavy-duty industrial, automotive, or marine applications.

Simplicity and Cost-Effectiveness: Mechanical temperature gauges are relatively simple in design and easy to maintain, which translates to lower cost compared to electronic temperature sensors. They also tend to have fewer failure points, making them reliable over long periods of use.

Readability: The analog dial is straightforward to read and doesn't rely on digital displays, which can sometimes be harder to interpret at a glance under certain conditions.

Limitations:

Limited Advanced Features: Unlike electronic gauges, mechanical temperature gauges typically do not offer advanced features like data logging, remote monitoring, or alarms.

Manual Calibration: Mechanical gauges can lose accuracy over time and may require periodic recalibration to maintain precise readings.

Mechanical Wear: The internal components, such as the bimetallic strip or gas capsule, can experience wear over time, especially in high-vibration or extreme temperature environments, leading to potential inaccuracies.