Digital Pressure Gauge-FAQ 

 

Introduction

A digital pressure gauge measures pressure and displays it in an integrated digital display. It converts the pressure into an electronic signal. The digital pressure gauge utilizes pressure transducers to indicate the pressure readings on the digital indicator.

This guide will help understand the functions, features, and applications of digital pressure gauges. At the end of this guide, you will know the basics of digital pressure gauges and how to install and use them.

1. What is a digital pressure gauge?

A Digital pressure gauge is an innovative instrument that measures pressure from liquid or gas and displays the results of its finding on the digital display. You don’t need an operator to read the pressure scale value as analog pressure gauges in digital readings. Instead, the transducer converts the value of pressure into an electronic signal.

A digital pressure gauge is a measuring instrument that uses battery power supply mode for installation and use. You don’t need to arrange the external power supply for running the digital pressure gauge. It is among the world-leading micro-processing technology with an advanced module conversion algorithm that ensures accuracy and power consumption.

2. What is the working principle of a digital pressure gauge?

Digital pressure gauges have become very popular in recent years. It uses pressure sensors to convert pressure into an electronic signal. There are various sensors, but the most common is a piezoresistive pressure sensor with piezoresistive elements. The diaphragm deflects because of the medium pressure. This deflection changes the cross-sectional area of piezoresistive elements that are linked to electrical resistance.

The power supply part of the digital pressure gauge consists of the required DC voltage. The regulated circuit supplies the circuit directly through the regulated circuit. The signal of the digital pressure gauge has the medium pressure that transmits the pressure sensing diaphragm of the sensor through the pressure interface. Finally, the electrical signal is sent to the CPU for processing, where it is displayed.

3. What are the technical features of a digital pressure gauge?

 

• The measurement range of the digital pressure gauge is 0.1-60MPa.
• The accuracy limit is +1, 0.5 FS.
• The sampling time is 1-5 seconds.
• There are 4 LCDs.
• The power supply battery is a 3.6V/2Ah industrial lithium battery with a warranty of 5 years.
• The maximum temperature limit is 20-50˚C wet: 90% RH overload capacity.
• The size of the pressure connection is ¼” NPT would be represented as 25 inches.
• It is battery-powered with a battery life of 1500 hours.
• The operating altitude is 10,000 ft.
• The LCD is 2.4 in/61 mm segmented LCD.
• The length of the digital pressure gauge is 1.75 in / 45 mm, and the width is 3.4 In / 87mm.

4. What are the specifications of a digital pressure gauge?

 

The operating pressure range is the maximum allowable pressure at which the equipment and system can operate safely. You can determine this range based on the expected pressure that the system can use. Mostly, in a digital pressure gauge, the value should not exceed 75% of the maximum range. For example, if your device has a maximum capacity of 100 psi, the operating range should not exceed 75 psi.

The readability requirements determine the dial diameter of the digital pressure gauge. The diameter is more significant for remote reading and more minor when the indicator and operator are closer. Usually, for accurate results, you need a larger dial size for displaying small pressure scale increments.

The minimum operating temperature of the digital pressure gauge is -20˚C, and the maximum operating temperature is 50˚C. The certifications of digital pressure gauge include CSA standard C22.2 No 61010-1, comply with Electromagnetic Compatibility Directive 2014/30/EU, and comply with Low Voltage Directive 2014/35/EU.

The relative humidity of the digital pressure gauge is 35 to 50˚C, and -10 to 35˚C. The media compatible for measuring the pressure includes air, alcohol, hydraulic oil, mineral oil, natural gas, transmission fluid, water, etc.

5. What are the features of a digital pressure gauge?

Before buying the digital pressure gauge, it is essential to ensure that the indicator is working accurately. Overall, the digital pressure gauge offers many advantages to its users. It has small size, easy to use with reliable performance and clear display. In addition, it has the features of accurately measuring the flow rate, liquid level, gauge pressure, and absolute pressure.

The digital pressure gauge has a computer control system to ensure automatic detection and control of the production process. The features of digital pressure gauge include:

• The automatic system of the digital pressure gauge provides high resolution and accuracy in the low-pressure range.
• It has an automatic shutdown feature, and the gauge shuts down after 40 minutes to save battery.
• The stable function stabilizes the reading and shows an average of the first four readings.
• The zero return function provides a fast one-click zero return.

6. What is the construction principle of a digital pressure gauge?

The digital pressure gauge follows the Bourdon principle, where the tube tends to straighten and regain the circular form when pressure is given. When the outside pressure increases, it pushes back on the membrane. The bending of the membrane results in the detecting of external pressure by the gauge. The purpose of the diaphragm is to respond to changes in pressure.

The digital pressure gauge has a bridge circuit that detects changes in capacitance. Pistons, vibrating elements, microelectromechanical systems (MEMS) are the other components of digital pressure gauges.

The pressure on the spindle at the contact point doubles through the system of gears and levers. Therefore, pressure sensors are an essential part of the instrument. The pressurized air pushes the piston towards the right when the pressure gauge is applied to the tire’s valve stem. The capacitance circuit detects this imbalance of the piston and converts it to a DC output current of 4 to 20 mA.

7. What are the pressure measurement techniques of a digital pressure gauge?

Digital pressure gauge measures pressure in different units. The absolute pressure is the pressure measurement technique relative to a perfect vacuum, where vacuum pressures are lower than atmospheric pressure.

The digital pressure gauge measures gauge pressure that is the most common pressure measurement technique. Gauge pressure is relative to atmospheric pressure. For example, sealed gauge pressure is comparable to one atmospheric pressure at sea level.

Differential pressure measures the difference between two input pressures. The digital pressure gauges display measurement in pounds per square inch (PSI), bars or millibars, inches or centimeters of mercury.

8. What are the selection considerations of a digital pressure gauge?

The digital pressure gauges come in several types and designs. Some digital pressure gauges are best for field use and are applicable for different locations. Other meters are best for a specific application, such as a pipeline, for continuous use. The defining characteristic of a digital pressure gauge from analog gauges is the need for a power source, so digital pressure gauges rely on battery power. Analog gauges, on the other hand, do not need a power source.

It would help if you were looking for the following specifications in the selection of digital pressure gauge for your application:

Gauge style

It would help if you considered whether the gauge pressure is used for measuring positive pressure, negative pressure, or both.

Case material

There are different case materials available, such as metal or plastic. The selection is made by considering the overall weight of the unit and environmental conditions.

Gauge wetted parts and connection.

The gauge wetted parts are the ones that come in direct contact with the pressure measuring media, such as liquid. The material of these parts should be compatible with the characteristics of the media. The gauge connection represents the port type that connects the gauge to the installation point.

Gauge accuracy

Gauge accuracy is the ability of the gauge to measure the actual pressure readings. It is shown in terms of +/- percentage of the full-scale tasks.

Gauge resolution

Gauge resolution is the granularity to which the gauge can register the readings. For example, the digital pressure gauge that measures psi with two decimal places will have a resolution of 0.01psi. This parameter is called gauge tolerance.

9. What are the advantages of digital pressure gauges over analog gauges?

Digital pressure gauges have some advantages over analog gauges.

• The digital pressure gauge has a digital display that provides readings in various pressure units, so no need for an operator to perform calculations.
• There are minimum chances of error with digital pressure gauges. Analog gauges have the operator’s position relative to the gauge dial that causes errors in the pressure readings. The numerical display in the digital pressure gauge reduces the chances of mistakes.
• The digital pressure gauges have backlit display capability, due to which you can easily take readings in low light conditions.
• The digital pressure units are available for different pressure ranges, while analog gauges are for predetermined pressure ranges.
• The digital pressure gauges are more precise than the analog gauges.

10. What are the types of digital pressure gauges?

 

JC 601 High Accuracy Digital Pressure Gauge

JC 601 High Accuracy Digital Pressure Gauge provides unique software processing technology. It has a five-digit large screen that makes clear data visibility.

Features of JC 601 digital pressure gauge are:

• The 3.6 Vdc lithium battery uses less power hence power consumption.
• In addition, it has five-digit large screens with a backlight function.
• Full-scale calibration function with zero point
• It has the latest software treatment technology and an RS232 communication port, making it easy to communicate with a PC.
• The alarm function that starts when the temperature exceeds
• The stainless steel structure that enhances robustness

For operating the JC 601 digital pressure gauge, you need to apply pressure on the pressure transducer that sends the signal. The signal is converted to digital data by the A/D converter. Then the microprocessor collects data and displays the final result on LCD.

§ Technical specification of JC 601 high accuracy digital pressure gauge

• The pressure range is up to 700 bars
• The gauge types include gauge pressure, compound pressure, absolute and differential pressure.
• The power battery includes DC3.6V lithium batteries, and the battery’s life is more than 1000 hours.
• The case material is aluminum, and wetted parts have stainless steel material.
• The working medium is oil, water, and non-corrosive gases.
• The temperature ranges from -10-50˚C, and humidity are less than 95%.

 

JC 602 High Accuracy Digital Pressure Gauge with HART

JC 602 High Accuracy Digital Pressure Gauge with HART is the latest digital pressure gauge with a double-line large screen with a backlight. It provides pressure measurement for pressure gauges, for calibrating pressure, and other pressure instruments. It is used for measuring pressure in various industries, such as power, chemical, petrol, metallurgy, etc.

§ Features of JC 602 High Accuracy Digital Pressure Gauge

• It has a pressure transmitting medium, including oil, water, and air.
• It has the feature of a 6-digit LCD screen with a backlight.
• Full-scale calibration function with zero point
• It has lightweight, small in size, and easy to operate.
• It provides short circuit protection.
• It supports HART version 5.
• It has a 7.4 Vdc lithium battery power supply and a unique charger
• The voltage measurement is 0-25V.

 

JC 108 High Accuracy Digital Pressure Gauge

JC 108 High Accuracy Digital Pressure Gauge is a high-precision pressure gauge with high precision measurement chips, temperature measuring circuit, voltage measuring circuit, and module. It is an economical and reliable solution for pressure applications where high accuracy is needed.

§ Features of JC 108 High Accuracy Digital Pressure Gauge

• The pressure range is 2500 bar.
• High accuracy up to ±0.025% FS
• It has a large, easy-to-read, and visible dual display with a six-digit resolution.
• It has full-scale calibration with zero points.
• The adjustable back time
• It has an 8.7.4 Vdc rechargeable lithium battery with a battery life of 80 hours.
• The JC 108 has a compact and cost-effective structure.
• The wetted parts have stainless steel material.
• The total height of the JC 108 digital pressure gauge is 166mm, and the weight is 0.75kg.
• It has a compensated temperature range from-10 to 50˚C.
• The humidity is less than 95%.
• The case material of the housing is plastic, while the wetted parts are 316 stainless steel.

JC Electric Contact Digital Pressure Gauge

JC Electric Contact Digital Pressure Gauge has a low-pressure contact switch that is mainly utilized for warning bell. It is a small, reliable, and lightweight pressure measuring element with switch function and indication and has a pressure indication dial and switch that are adjustable over different pressure ranges. In addition, it has a sizeable visible LCD that makes it possible to understand the readings.

For maximum performance, select a full-scale pressure range that shows operating pressure. Operating pressure should not exceed three-quarters of the full-scale range for constant pressure and two-thirds for fluctuating pressure.

Digital Differential Pressure Gauge with three-way manifold

Digital Differential Pressure Gauge with a three-way manifold is the pressure measuring tool. The manifold in the digital pressure gauge simplifies mounting when using differential pressure or measuring pressure, and the design of the manifold adds versatility and user convenience. All the process connections are made through the manifold.

Digital Differential Pressure Gauge with three-way manifold has two threaded inlets for high and low process connections. It has two block valves, high and low-pressure block valves, and one equalizing valve. A three-way manifold in digital pressure gauge ensures that the capsule will not be over ranged.

Digital Differential Pressure Gauge

Digital Differential Pressure Gauge is the highly accurate digital pressure gauge that provides better performance and more accurate readings.

§ Features of the digital differential pressure gauge

• It has an output of 4-20mA and is perfect for applications that use a gauge and a transmitter.
• It has the universal power of 24-240 VAC and VDC that provides greater flexibility.
• It has total programmable relay outputs, including setpoints, time relays, and relay action.
• The accuracy of the digital differential pressure gauge is 1%, 0.5%, and 0.25%.
• It has an easy read and visible backlit LCD.
• It has a wireless transmitter option that sends readings to remote locations. In addition, it includes charting and data logging software.
• It has a rugged stainless steel structure with a precision of 0.08% accuracy.
• The storage temperature ranges from -40 to 82˚C, and the operating temperature ranges from -18 to 66˚C.
• The user-selectable display rate is from 0.25 to 10 sec.

11. How to calibrate a digital pressure gauge?

A digital pressure gauge needs calibration multiple times to ensure the smooth functioning of the equipment. Field calibration is an excellent quick way to get your digital pressure gauge back to proper working. In addition, calibration is essential for fixing minor drifts, installation shifts, or other minor issues. Generally, there are three ways to perform a field calibration of the digital pressure gauge.

• Use tare to reset the zero.
• Adjust the range to shift the span
• Quick Cal to reset zero and also span

Use tare to reset the zero

The tare function ignores the existing pressure to measure the change in pressure. You can do that by moving the reference point from zero to current stress. Using tare to zero gauges is an excellent way to deal with barometric changes. Zero references cannot compensate for barometric pressure, so tare the gauge ensures accurate measurement.

Adjust the range to shift the span

You need to pressure up the gauge to full scale. Once fully pressurized, you can reset the full scale using the range to adjust the setting. For example, you can adapt it full scale 5% up or down.

Quick Cal to reset zero and span

After resetting the endpoints, use the quick Cal feature. You can do an installation shift when the gauge is over-torqued. A slightly compressed diaphragm needs calibration, and Quick Cal can help fix the installation error in the field.

 

12. What are the disadvantages of digital pressure gauges?

Apart from the number of advantages, there are some disadvantages of digital pressure gauges as well. The main disadvantage of a digital pressure gauge is, it is not easy to see the full scale and read oscillating values. Furthermore, for operating the digital pressure gauge, you require power. Also, the readings are not visible from a distance.

You cannot see the trend of value changes, and it is essential to have a power supply, such as battery power supply, loop power supply, and solar power supply. Also, batteries can be risky, and you cannot depend on them entirely as they may drain at the most critical times.

13. What are the applications of a digital pressure gauge?

Digital pressure gauges are reliable instruments and require minimal moving parts. The only moving part of the instrument is the diaphragm. As a result, Digital pressure gauges are a better measurement tool as they can withstand overpressure without causing any damage.

Digital pressure gauge is used in various industries, such as pharmaceutical, food processing, metallurgy, and automotive applications. It has a battery long-term power supply mode that is easy to install and use. It is also applicable in the electric power, chemical industry,  and other related fields.

14. What are the factors to consider while powering digital pressure gauges?

The main disadvantage of using the digital pressure gauge is the use of a battery-powered pressure gauge. The battery needs replacement that can be unpredictable, but at the same time, it offers flexibility and reliability. The standard battery time with the most extended battery life is 4000 hours. 4-20Ma loop-powered digital pressure gauge ensures that the readings are available without worrying about the battery life.

The advantage of the loop power is that the cable provides power to the unit can provide the analog output proportional to the pressure. The solar power gauges provide almost the same features as the battery-powered gauges, and they need a constant source of light. The advantage of solar power in digital pressure gauges is that you don’t need to rely on batteries that eventually need replacement.

Conclusion

Digital pressure gauges are essential tools that convert applied pressure into signals and then numerically display the results. At Instruthink, we are specialized in the production of digital pressure gauges. In addition, we have experts in our field that will assist you in purchasing the digital pressure gauge that accommodates your specific requirements.

We are the market leader in digital pressure gauges and provide the most competitive prices of our products without compromising on quality. So if you are looking for low-cost digital pressure gauges, contact us without any delay.