How To Select a Pressure Gauge and Keep It Well Calibrated
I’ll cut to the chase. If you follow these tips, you can rest assured that you will keep your pressure gauge calibrated at all times. But you know what? I don’t care!
Calibrating a pressure gauge is not a one time job that can be forgotten about as it requires regular calibration. The pressure gauge tends to waver from its specified range and starts to give false readings that affect the quality and safety leading to false readings.
How Frequently Should My Pressure Gauge be Calibrated?
Pressure gauge calibration helps in ensuring that your instruments are all running and functioning as per their designation, resulting in accurate results. Regular and proper calibration is particularly important in the food and pharma sectors as proper calibration is part of quality assurance and compliance requirements.
Pressure gauge calibration is important but you need to know when and how often you need to calibrate your gauge. The two most important factors that affect your pressure gauge are its stability, and its application.
3 Things to Consider when Calibrating Your Pressure Gauge
Manufacturer’s Recommendations
Follow the manufacturer’s guidelines on how to calibrate your instruments and how often calibrations should happen. The chances are that your equipment will usually come with a data sheet that holds the stability specifications that should occur between the different calibration intervals, take these into account while setting a schedule.
Critical Locations
Instruments which are used to measure the pressure changes in economically important locations may need to be calibrated more often. For instance, pressure transducers located near volatile materials or exposed to environmental changes should be calibrated more often.
Installations or Changes
Always calibrate your equipment directly after having it installed as well as when you make any changes to the installation location.
7 Tips for Selecting Your Pressure Gauge
Gauge Accuracy
The accuracy of the pressure gauge is defined either as a percentage of a full-scale range or a percent of the span. The better the accuracy of the gauge, the costlier it will be, which is why the application of the gauge needs to be carefully considered when deciding the level of the accuracy. This use tends to vary from industry to industry.
Mounting
You need to bear the connection location in mind when you select your pressure gauge. There are quite a lot of mounting options that are available. Some of these options are:
Range
It is important that you choose a pressure range that is roughly twice the average operating pressure. Make sure that the maximum operating pressure does not surpass 75% of full range as this may lead to fatigue failure of the pressure sensor inside the gauge. If there should happen to be pulsation during the process then the operating pressure should not surpass 50%.
Display Type
Pressure gauges are made in two designs which are analogue and digital displays. The traditional analogue display has been the most commonly used but the digital display is rapidly catching up. The application of the gauge usually tends to determine what kind of display is needed.
Connection Size
Pressure gauges are available in both the bottom and back connections. The pressure gauges are available with a number of connections which include NPT, DIN, JUS, BSP and SAE. The most widely used connection sizes are ¼” NPT and ½” NPT. Consider the following factors when you are choosing a gauge:
Environment
The environmental factors that usually have to be considered when choosing your pressure gauge is the temperature in the area where it will be used. Here are some other factors that should be kept in mind:
Gauge Size
The dials of the pressure gauges range from 1.5’ to 16’ in diameter. The size of the dial is usually determined by the ease with which the gauge can be read, accuracy requirements and space limitations.
Understanding how to calibrate your pressure sensor is the first step towards preventing measurement inaccuracies, damage and safety issues.
Edward Simpson works for RS Calibration Services and has a knack for finding faults in machines and does not rest until they are rectified to perfection. He lives in Pleasanton, CA and loves to write about how machines work and about the importance of proper care and calibration of equipment. When he's not working or writing, he loves to run to stay fit.