When choosing a pressure gauge, digital and analog pressure gauges are two common options and each type has its unique advantages. This article will help you understand the differences between these two types of pressure gauges and help you make the best choice.

Understanding Digital Pressure Gauge

A digital pressure gauge is a device that displays pressure readings via an electronic display screen. It uses a sensor to convert pressure signals into electrical signals and provides accurate pressure readings through a digital display. Compared to traditional analog pressure gauges, digital pressure gauges generally have higher accuracy and easier-to-read display interfaces that make them particularly suitable for applications requiring high-precision measurements.

Exploring Analog Pressure Gauge

Analog pressure gauges use a mechanical pointer to indicate pressure values on a dial. They convert pressure into a visible pointer position through the action of springs and mechanical components. Although analog pressure gauges are simpler in structure and lower in cost, their accuracy and readability are not as good as digital pressure gauges especially in low light or complex environments where readings may be limited.

How to Determine if a Device is Analog or Digital?

The most direct way to determine whether a device is analog or digital is to check the display method. Analog pressure gauges typically have a dial and a pointer, while digital pressure gauges display the reading via an LCD or LED screen. Digital pressure gauges offer a more intuitive display and reduce the risk of human error.

Pros and Cons of Digital & Analog Pressure Gauge

Feature	Digital Pressure Gauge	Analog Pressure Gauge
Accuracy	High (±0.5% FS or higher)	Lower (typically ±1.6% FS)
Readability	Good (digital display, no parallax)	Poor (due to parallax and estimation errors)
Vibration/Shock Resistance	Excellent (no moving parts)	Poor (pointer jitter, prone to damage)
Power Requirements	Required	Unrequired
Cost	Higher	Inexpensive
Function	Output, control and recording	On-site instructions only
Response Speed	A slight delay	Real time
Ambient Temperature	There is an upper limit to the scope of application.	It can withstand higher temperatures
Maintain	Complex, usually requires replacement	Simple, can be adjusted locally

Pros of Digital Pressure Gauges

High Accuracy and High Resolution: Digital pressure gauge’s accuracy typically reaches ±0.5% FS or higher, while analog gauges are generally ±1.6% FS. It can display very small pressure changes.

Superior Readability

• Parallax-Free: Direct digital display completely eliminates errors caused by different viewing angles when reading pointer dials.
• Intuitive Readings: No need to estimate the pointer’s position between two scales that reduces human error.

Rich Intelligent Functions

• Peak Recording: Automatically records and displays the maximum and minimum values ​​during measurement that is necessary for analyzing system shocks and fluctuations.
• One-Button Unit Switching: Easily switch between units such as MPa, bar, psi, kgf/cm², etc.
• Data Output: Equipped with 4-20mA, RS485 and other signal outputs, easily connecting to PLCs, DCSs or data acquisition systems for remote monitoring and automation.
• Alarm Control: Upper and lower limits can be set and control signals can be output via relays to achieve automatic alarms or equipment start/stop.

Superior Stability and Environmental Interference Resistance

• Vibration and Shock Resistance: With no internal moving mechanical parts, the pointer will not jitter in vibrating environments that ensure stable readings and a longer lifespan.
• No Mechanical Wear: Its performance will not degrade due to mechanical wear over time or with frequent use.

Cons of Digital Pressure Gauges

• Requires Power: Must rely on batteries or an external power source to operate.
• Higher Cost: Initial purchase cost is typically higher than analog gauges with the same range.
• Limited Environmental Tolerance: Extreme temperatures (e.g., sustained temperatures exceeding 70-85°C) may affect the lifespan and stability of the electronic components in digital pressure gauges, while some mechanical gauges can withstand higher temperatures. It may also need additional protection in environments with strong electromagnetic interference.
• Complexity: The internal electronic circuitry is more complex than the mechanical structure that make on-site repair difficult and often require factory return or module replacement.
• Response Speed: When displaying rapid, high-frequency pressure fluctuations, its sampling and refresh rates may not keep up, while analog gauges offer real-time pointer response.

Pros of Analog Pressure Gauges

No External Power Required: Purely mechanical structure and operation based on its own deformation. This is a significant advantage in critical safety applications or passive environments.

• Low Cost: Simple structure, low manufacturing cost and very economical purchase price.
• Rugged & Durable & High Temperature Resistant: Well-designed mechanical gauges can withstand higher ambient temperatures and operating overpressures.
• Real-Time Response: The movement of the analog pressure gauge pointer is almost synchronous with pressure changes that provide a very intuitive display of dynamic pressure fluctuations.
• Long-Term Stability and Reliability: Under stable operating conditions, a high-quality analog gauge can operate reliably for many years. The analog pressure gauge’s technology is very mature.

Cons of Analog Pressure Gauges

Lower Accuracy, with Reading Errors:

• Generally Lower Accuracy (e.g., ±1.6% FS)
• Parallelism: When reading values, the line of sight must be perpendicular to the dial; otherwise, errors will occur.
• Estimation Required: When the pointer is between two graduations, manual estimation is required that result subjective errors.

High Mechanical Sensitivity

• Susceptibility to Vibration: In vibrating environments, the pointer will jitter violently that make readings difficult and potentially damaging the movement over time.
• Susceptibility to Pulses:Frequent pressure pulses accelerate the fatigue aging of elastic components such as the Bourdon tube that lead to permanent drift or damage.
• Existence of Mechanical Wear: Internal gears and shaft tips will wear over time that cause a gradual decrease in accuracy.
• Limited Functionality: Most gauges only provide local indication and cannot perform remote data transmission, recording or control.
• Limited Measuring Range: Measurements of extremely high or low pressures are difficult to manufacture that drastically increase costs.

How to Convert Analog Signals to Digital Signals?

In some applications, it may be necessary to convert analog signals to digital signals for further processing. This process is typically accomplished using an analog-to-digital converter (ADC). The ADC converts the voltage signal from the analog pressure gauge into digital data that allow digital devices to perform more efficient data processing and display.

Choosing the Right Pressure Gauge for Your Needs

Choosing between a digital or analog pressure gauge depends on your specific needs.

If high accuracy and easy-to-read pressure data are required, a digital pressure gauge is clearly the better choice. It is suitable for applications requiring precise measurement and data logging such as laboratories and industrial equipment monitoring.

However if the budget is limited and the environmental conditions are relatively simple, an analog pressure gauge may be a more economical and reliable choice.

Final Thought

By comparing the advantages and disadvantages of digital and analog pressure gauges, you can make the best choice based on your actual needs. If you are still unsure which equipment is right for you, the ZJSHEGF team is ready to help you.