Analogue Pressure Gauge Calibration

A basic summary of our NATA accredited scope:

Pressure:

We can calibrate virtually all pressure reading devices

• Up to 415MPa / 60,000PSI
• 0.009% Uncertainty capable for precision devices up to 105MPa (15,000PSI)
• Excellent low pressure capability – 0.65Pa uncertainty on draught pressures
• Barometers and absolute pressure transmitters with current, voltage or frequency outputs

Electrical:

DMMs, Meters, Calibrators

• DC Voltage up to 1050V, from 5ppm uncertainty
• DC Current up to 30A, from 20ppm uncertainty
• AC Voltage and Current 10Hz to 100 kHz, from 0.02%
• Resistance up to 10 GΩ, Capacitance up to 200 mF

HV Insulation and Continuity

• Insulation Resistance up to 10GΩ, 10kV test voltage
• MicroOhm Continuity from as low as 1μΩ at 100A test current

Frequency and Time

• Frequency calibration up to 100 MHz on counters, meters, calibrators or testers.  From 5 μHz uncertainty
• RCD Testers, trip time uncertainty from 0.3ms

Resistor Sets and Decade Boxes

• Standard Resistors, Calibration Boxes,
  Insulation Test Boxes, Decade Boxes etc…
  From 10 μΩ to 10 GΩ

Bench testing an analogue gauge is a precise process aimed at ensuring the gauge’s accuracy and reliability. Below is a step-by-step guide on this procedure:

Preparation

Cleaning

Before testing, clean the gauge thoroughly to ensure that no dirt or debris interferes with its operation or your reference equipment.

Inspection

Check the gauge for any signs of damage or wear. Any defects could affect the accuracy of the test.

Reference Equipment

Ensure all necessary testing equipment is available, functional and is within its required calibration interval. This includes a reference gauge/module, a pressure source, any required connectors or adapters, and finally ensure access to any applicable calibration standard you may be required to follow (e.g. MSA Test Method 2).

Environmental Conditions

Take note of environmental conditions (temperature, gauge positioning etc.) to report these along with the results as ‘test conditions’.

Connection

Securing the Gauge

Attach the gauge securely to the test bench. This involves making sure that all connections are tight and leak-free, ensuring safety.

Setting up Test Equipment

Connect the gauge to the standard pressure source. Ensure that all connections between the gauge, the pressure source, and the reference gauge are secure and correctly configured.

Execution

Running the Test

Apply pressure from the standard source to the gauge being tested. Monitor the gauge’s response and compare its readings to that of the reference gauge.

Observing Responses

Pay attention to how the gauge reacts to changes in pressure. Note the speed of response and any lag in the readings.

Documentation

Recording Results (Error)

Document any differences (gauge error) between the gauge’s readings and the reference gauge’s. Note the conditions under which these differences occur.

Evaluating Acceptability

Assess whether the variances are within acceptable limits for the gauge’s intended use. This may involve the use of a calibration standard (e.g. MSA Test Method 2).

Maintaining Records

Keep a detailed record of the test results for future reference and quality control purposes.

Case and Ring

This part of the pressure gauge is the protective shield, safeguarding the internal components from external elements like dust, moisture, and mechanical impact.

The case is typically made from robust materials like stainless steel or plastic, and it houses all the internal parts of the gauge. The ring is usually a circular component that secures the face or the glass of the gauge, adding an extra layer of protection and often enhancing the aesthetic appeal of the device.

Dial and Pointer

The dial and pointer are the most visible parts of a pressure gauge and are collectively known as the face of the gauge. The dial usually features numerical markings indicating pressure levels, and it may have different scales depending on the type of pressure being measured (e.g., psi, bar, kPa). The pointer, which is a thin, needle component, moves over the dial to indicate the current pressure reading. The clarity and precision of the dial and pointer are crucial to ensure accurate measurements.

Bourdon Tube

Is a curved, flexible tube that changes shape in response to the fluid or gas pressure inside, resulting in the movement of the pointer, and thus the indicated pressure on the face of the gauge.

Movement

A critical component that translates the mechanical motion of the Bourdon tube into a readable indication on the dial.

This mechanism typically involves a series of gears and linkages that amplify the small movements of the Bourdon tube into a larger, more discernible motion of the pointer across the dial. 

When choosing between digital and mechanical pressure gauges, it’s essential to consider the specific requirements of your application, including factors like precision, durability, environmental conditions, and budget. 

Digital Pressure Gauges

High Precision

A digital pressure gauge is known for its higher precision and accurate measurements. They often feature advanced sensors that provide exact measurements, which can be crucial in applications where precise pressure monitoring is necessary.

Easy to Read

These gauges typically have a clear digital display, often an LCD, which shows the pressure gauge reading in an easy-to-read format. This can be particularly advantageous in low-light conditions or where quick, unambiguous readings are required.

Cost Considerations

Generally, digital gauges are more expensive than their mechanical counterparts. This is due to their more complex technology and additional features. The cost might be a significant factor, especially for large-scale deployments or where budget constraints are tight.

Mechanical Gauges

Durability

Mechanical gauges are typically more robust and better suited for tough conditions. They are less sensitive to dust and moisture, making them ideal for industrial environments or outdoor applications.

No Power Requirement

These gauges operate purely mechanically and do not require any power source. This makes them more suitable for use in remote or off-grid locations.

Maintenance and Attention

Mechanical gauges might require more frequent calibration and maintenance to ensure accuracy. They are also more prone to wear and tear due to their moving parts.

All services including repairs and calibrations are subject to our standard terms and conditions