Digital Hydraulic Pressure Gauge for Pressure Measurements

Frequently Asked Questions About Selecting and Using Digital Hydraulic Pressure Gauges

The correct measurement range and a pressure measurement point that is suitable for the hydraulic system are crucial for obtaining meaningful measurements. Digital pressure gauges make it easier to read measurements and, depending on the model, can also store and document measurement values. Here, we answer frequently asked questions about the selection and use of digital hydraulic pressure gauges.

• What is a digital hydraulic pressure gauge?

  A digital hydraulic pressure gauge is an electronic pressure measuring device used to measure and digitally display pressures in hydraulic systems.

  Unlike an analog dial pressure gauge, the measured value is displayed directly on a screen.

  Depending on the model, additional functions such as:

  • Min/Max values
  • Peak value display
  • Data logging
  • Measurement value storage
  • USB data transfer

  may be available.

• For which applications are digital hydraulic pressure gauges suitable?

  Digital pressure gauges can be used in a wide range of mobile and stationary hydraulic systems.

  Typical applications include, for example:

  • Agricultural machinery
  • Construction machinery
  • Forestry machinery
  • Commercial vehicles
  • Municipal machinery
  • Material handling equipment
  • Industrial and stationary hydraulic systems

  Key factors include the required measurement range, the type of connection used, and the gauge’s compatibility with the respective medium.

• What media can be measured using the DM-80 digital pressure gauges?

  The DM-80 product family is specifically designed for pressure measurements in hydraulic systems using oil and water.
  
  Before use, verify that the sensing cell, seals, and connections are suitable for the specific medium and the intended operating conditions.

• What are the measurement ranges for the DM-80 digital pressure gauges?

  The DM-80 product family covers a wide range of pressure ranges.

  Currently available models include, among others:

  • -50 to +50 mbar
  • -200 to +200 mbar
  • -1 to +16 bar
  • 0 to 25 bar
  • 0 to 60 bar
  • 0 to 100 bar
  • 0 to 250 bar
  • 0 to 400 bar
  • 0 to 600 bar
  • 0 to 1,000 bar
  • 0 to 2,500 bar

  are available.

  The DM-80-UMS devices with data loggers also offer a selection of different measurement ranges.

• What measurement range should I choose for my hydraulic system?

  The measurement range should be appropriate for the expected operating pressure and the maximum possible system pressure.

  As a general rule:

  • the expected pressure must fall within the permissible measurement range,
  • possible pressure spikes must be taken into account,
  • and the measurement range should not be unnecessarily large.

  Precisely because the measurement accuracy for the corresponding DM-80 models is specified relative to the full-scale value, selecting a measurement range appropriate for the application can be advantageous for obtaining more meaningful measurements.

• Why shouldn't the 2,500-bar pressure gauge always be used?

  The widest possible measurement range is not automatically the best choice.
  
  If, for example, a hydraulic system with a significantly lower operating pressure is to be tested, a properly selected pressure gauge is generally more appropriate.
  
  The wide measurement range of 2,500 bar is required for applications where such high pressures can actually occur.
  
  For typical industrial hydraulics, however, 250-, 400-, or 600-bar models may be more suitable.

• What does an accuracy of ±0.5% FS mean?

  FS stands for “Full Scale,” or the full-scale value.
  
  The specified accuracy therefore refers to the maximum value of the respective measurement range and not to the currently displayed measurement value.
  
  For this reason, the measurement range should be selected as appropriately as possible to match the expected pressures.

• What is the difference between resolution and accuracy?

  Resolution describes the smallest increments in which a measuring instrument can display a value.
  
  Accuracy, on the other hand, describes how much the displayed measurement value may deviate from the actual value.
  
  A high number of displayed decimal places therefore does not automatically mean a correspondingly high level of measurement accuracy.
  
  The technical accuracy specifications are crucial for evaluating a measuring instrument.

• What does the min/max function on a digital pressure gauge mean?

  The Min/Max function displays the lowest and highest pressure values recorded during a measurement.
  
  This is helpful, for example, when the hydraulic pressure fluctuates during a machine operation or when short-term pressure spikes occur.
  
  This means the technician does not have to constantly look at the display to identify the highest or lowest recorded value.

• What is the peak value display?

  A peak value display helps identify short-term spikes in pressure.
  
  This can be particularly helpful during dynamic hydraulic operations in which the pressure rises sharply for only a short time.
  
  Such values should always be evaluated in relation to the permissible system pressures and the manufacturer’s specifications.

• What is the difference between the DM 80 and the DM 80 UMS?

  The DM-80 devices are primarily used for digital pressure measurement and display.

  The DM 80 UMS model also features an internal data memory.

  This allows measurements to be recorded, saved, and then transferred to a computer via USB.

  The UMS model is therefore particularly suitable when pressure trends need to be documented or analyzed at a later time.

• How does the DM 80 UMS data logger work?

  The measurement is started directly on the digital pressure gauge.
  
  The recorded measurements are stored in the device's internal memory.
  
  Once the measurement is complete, the digital pressure gauge can be connected to a computer via USB, and the stored measurement file can be transferred.
  
  This makes the device suitable for longer measurements where more than just a single instantaneous value needs to be recorded.

• In what file format is the measurement data saved?

  The DM-80-UMS devices save measurement data in CSV file format.
  
  CSV is a widely used format for tabular measurement data.
  
  This allows the saved values to be further processed using appropriate spreadsheet and data analysis programs.

• Do I need special software to read data from the DM 80 UMS?

  No additional specialized transfer software is required for data transfer alone.
  
  Once connected via USB, the device is recognized by the computer as a data storage device.
  
  The saved CSV files can then be copied to the computer and analyzed using appropriate software.

• Can the measurement data be analyzed using Microsoft Excel?

  Yes.

  The saved CSV files can be opened and further processed in Microsoft Excel or other programs, for example.

  This allows you to, among other things:

  • Create tables of measurement values
  • Display pressure trends
  • Evaluate maximum and minimum values
  • Document measurements
  • Compare different measurements

  The actual evaluation is then performed independently of the pressure gauge.

• When is it useful to record the pressure curve?

  Data logging can be particularly helpful when a fault:

  • occurs only intermittently,
  • manifests under load,
  • occurs during a prolonged operating cycle,
  • occurs as the temperature rises,
  • is characterized by short-term pressure spikes.

  Instead of simply reading a single pressure value, the trend over a defined period of time can be analyzed.

• Can the data logger be used to detect internal hydraulic leaks?

  The data logger itself does not automatically detect leaks.
  
  However, a recorded pressure curve can provide clues if, for example, pressure that has built up under defined conditions drops unusually quickly.
  
  Whether this is actually caused by an internal or external leak must then be determined through further testing.

• Can a hydraulic system have the correct pressure and still be faulty?

  Yes.

  A correct pressure reading alone does not prove that the entire hydraulic system is functioning properly.

  For example, problems can occur with:

  • flow rate
  • internal leakage
  • temperature
  • pump
  • valves
  • hydraulic motors
  • cylinders

  If flow rate and temperature need to be evaluated in addition to pressure, a digital hydraulic diagnostic tool for pressure, flow rate, and temperature is the more comprehensive solution.

• When is a digital pressure gauge sufficient for hydraulic diagnostics?

  A digital pressure gauge is particularly well-suited when you need to answer a specific question about pressure.

  For example:

  • Is the specified system pressure being maintained?
  • What is the pressure at a specific measurement point?
  • Are there pressure differences between two measurement points?
  • Are there any unusual pressure spikes?
  • How does the pressure change during a specific operation?

  For tasks like these, a simple pressure measurement may be sufficient.

• When should I use a hydraulic diagnostic tool instead of a pressure gauge?

  If, in addition to pressure, flow rate and hydraulic oil temperature are also relevant for troubleshooting, a simple pressure gauge is not sufficient.

  In this case, a digital hydraulic diagnostic device for pressure, flow, and temperature is suitable.

  This allows for the simultaneous evaluation of several important hydraulic parameters.

• Can I measure two hydraulic pressures at the same time?

  Yes.

  To do this, two digital pressure gauges can be used at different measurement points.

  This is particularly convenient when using a digital hydraulic test kit equipped for this purpose or a hydraulic test strip for multiple measurement points.

  This allows pressure differences or different hydraulic circuits to be compared with one another under the same operating conditions.

• What is the advantage of a hydraulic test kit over a single digital pressure gauge?

  A single digital pressure gauge is a good choice if you already have the appropriate hoses and fittings, or if you only need to test a specific measurement point.

  A digital hydraulic test kit, on the other hand, combines the following depending on the model:

  • one or more digital pressure gauges
  • test hoses
  • test connections
  • adapters
  • other accessories

  in a portable system.

  This is particularly suitable for multi-brand service centers, repair shops, and mobile service technicians.

• When is a hydraulic test bench useful?

  A hydraulic test panel is particularly helpful when you need to set up multiple pressure measurements on a regular basis or quickly compare different pressure ranges.

  The pressure gauges are clearly arranged on a single unit.

  This reduces the effort involved in repeatedly setting up multiple individual pressure gauges.

• Can the digital pressure gauge be screwed directly onto the hydraulic system?

  That depends on the measurement point, connection, and application.

  In many cases, a pressure gauge is connected to the hydraulic system via:

  • a measurement hose
  • a test connection
  • a quick-connect coupling
  • an adapter.

  This allows the pressure gauge to be positioned outside areas that are subject to movement or are difficult to access.

• What type of pressure connection do the DM-80 digital pressure gauges have?

  Depending on the model, the appropriate pressure connections are available.
  
  For example, current UMS models use a G-1/2-B connection.
  
  Other pressure connections and measurement ranges may be available depending on the product or application.
  
  Therefore, before placing an order, you should verify which connection is required for your existing measurement system.

• Why are measuring hoses used in hydraulic measurements?

  A suitable measuring hose allows the pressure to be transmitted from the actual test point to the pressure gauge.

  This enables the measuring device, for example:

  • to be read more easily,
  • to be positioned away from moving components,
  • to be used at hard-to-reach measurement points.

  The measuring hose, connections, and adapters must be suitable for the pressure involved.

• Can using the wrong test tube be dangerous?

  Yes.

  Hydraulic systems can operate at very high pressures.

  Hoses, couplings, and adapters must therefore be suitable for:

  • the maximum possible pressure,
  • the fluid being used,
  • and the operating temperature.

  Damaged or unsuitable components must not be used.

• What should you pay special attention to when taking blood pressure readings?

  At high hydraulic pressures, a properly configured measurement setup and suitable high-pressure components are particularly important.

  Before taking a measurement, the following should be checked:

  • permissible system pressure
  • pressure gauge range
  • pressure resistance of the hoses
  • adapters and couplings
  • condition of all connecting parts.

  Hydraulic fluid under high pressure can cause serious injury in the event of a leak.

• When do you need a 1,000- or 2,500-bar digital pressure gauge?

  Such high-pressure models are only required for applications in which correspondingly high pressures may occur.
  
  They are not automatically the best choice for standard hydraulic systems.
  
  The measurement range must always be based on the actual application.
  
  Lower measurement ranges are better suited for many mobile hydraulic applications.

• What are the very low measurement ranges of ±50 and ±200 mbar used for?

  Very low or bidirectional measurement ranges are intended for specialized pressure and differential pressure applications.
  
  They are not designed for typical high-pressure hydraulic systems.
  
  The appropriate model depends on the specific measurement task.

• Can the DM-80 pressure gauges measure negative pressure?

  Models with a negative measurement range can also measure pressure values below the atmospheric reference pressure.
  
  One example is the -1 to +16 bar model.
  
  Whether this measurement range is suitable for a particular application must be determined based on the specific test requirements.

• Do all DM-80 devices have a data logger?

  No.
  
  The internal data memory is a feature of the UMS model.
  
  If you only need to display measured values directly or monitor minimum/maximum values, a standard DM-80 model may be sufficient.
  
  For recording measured values and later PC analysis, you should choose the appropriate DM-80 UMS version.

• Are the DM-80 devices powered by a rechargeable battery or a regular battery?

  The power supply varies depending on the model.
  
  Within the DM-80 product family, there are battery-powered devices as well as models with a built-in rechargeable battery.
  
  The current DM-80-UMS devices feature a high-performance rechargeable battery.
  
  Before making a selection, you should therefore check the technical specifications of the specific model.

• How long does the battery in a DM 80 UMS last?

  Leitenberger states that current DM-80-UMS models have a battery life of up to about ten hours.
  
  Actual battery life may vary depending on usage, display functions, and operating conditions.

• Is the display readable in low light?

  The current DM-80-UMS models feature a backlight.
  
  In addition, the display can be rotated approximately 330°.
  
  This allows the display to be oriented toward the user regardless of the installation orientation.

• Why is a rotatable display useful for hydraulic measurements?

  Hydraulic measuring points are often located in hard-to-reach or awkwardly positioned areas.
  
  A rotatable display allows the technician to better position the screen toward them after connecting it.
  
  This makes it easier to read the display directly on the vehicle or machine.

• Are DM-80 digital pressure gauges also available in complete test kits?

  Yes.

  Digital pressure gauges from the DM-80 series are used both individually and as part of complete hydraulic test kits.

  A test kit is particularly useful when you also need matching hoses, test fittings, and adapters.

  You can find the corresponding solutions under digital hydraulic test kits.

• For which repair shops is a digital hydraulic pressure gauge a worthwhile investment?

  Digital hydraulic pressure gauges are particularly suitable for:

  • Agricultural machinery repair shops
  • Construction equipment service centers
  • Commercial vehicle repair shops
  • Municipal and forestry equipment
  • Forklift and material handling equipment service centers
  • Mobile service technicians
  • Industrial maintenance

  They are especially useful in applications where hydraulic system pressures must be regularly checked or documented.

  You can find additional solutions for pressure, flow, and temperature measurements under Test and Diagnostic Equipment for Hydraulic Systems.