This guide provides an overview of measuring vacuum pressure including suggested vacuum measurement products and question & answers relating to using and selecting vacuum measurement sensors & instrumentation.
Vacuum is the range of pressure which lies between zero absolute pressure (perfect vacuum) and atmospheric pressure.
Vacuum Pressure Transmitters - Choose vacuum pressure transmitters for measurements over the low vacuum range of 25 to 760 Torr, using a absolute or negative gauge reference vacuum range.
Vacuum, Suction Pressure Data Loggers, Recorders - Select vacuum data loggers for precise recording of negative suction and absolute pressures. Ideal for process analysis, test reports, and system validation in industrial and research settings.
Vacuum Pressure Transducers - Explore vacuum pressure transducers with voltage outputs (0-5V, 0-10V, 0.5-4.5V). Select absolute or gauge references for partial/full vacuum ranges.
Vacuum Range Calibration Equipment - Maintain the accuracy of your vacuum sensors, gauges, and switches with high-quality vacuum calibration equipment.
DM01 Multi-Range High Accuracy Pressure Gauge
DPS200 HVAC Differential Pressure Transmitter
IMPLR Low Range All Stainless Steel OEM Pressure Sensor- IMP Low Cost Pressure Sensor
DPS300 User Switchable Pressure Range, Volts or Current Output Low DP Sensor- LEO Record (Ei) Pressure Data Logger
DS200P Sanitary Low Range Pressure Gauge, Switch and Sensor
DPS Low Differential Pressure Transmitter
DMK457 Marine Approved Pressure Transmitter
DMP457 Marine Approved Pressure Transmitter
Baroli 02 Precision Digital Pressure Gauge
Baroli 02P Low Range Flush Diaphragm Digital Pressure Gauge
ATEX approved negative 10 mbar vacuum pressure transmitter - ATEX certified intrinsically safe pressure transmitter for measuring from 0 to minus 10 millibar gauge vacuum pressure.
Portable vacuum sensor tester for industrial control loop set-point validation - High precision vacuum calibration kit designed for technicians verifying sensor set-points from atmospheric pressure down to -0.95 bar with fine-tuning control.
-760mmHg to +20 kg/cm² pressure transmitter with HART coms - Compound range transmitter for sensing pressure from -760 mm of mercury vacuum to 20 kilograms per sq cm positive pressure with HART communication.- 400 mbar absolute (not relative) battery supplied vacuum sensing display - Battery supplied digital readout display for sensing the absolute pressure of a vacuum below 400 mbar.
50 kPa absolute vacuum air pressure gauge with 1/4 NPT male fitting - Absolute vacuum pressure gauge for portable use in air measurement applications, capable of measuring 0 to 50 kPa abs pressure with 1% accuracy and connected using a 1/4 NPT male fitting.- -100 mbar digital vacuum gauge - Measure vacuum down to -100 mbar with this digital vacuum gauge. Ideal for industrial and laboratory applications.
Vacuum gauge for minus 150 mbar range with a 0.1 mbar display resolution - We are looking to measure have to measure vacuum from zero to -150mbar to a resolution of 0.1 milibar- Digital vacuum/pressure recorder to replace circular paper chart - Upgrade your timber treatment process with the DM01 digital vacuum/pressure recorder. Accurate, reliable, and easy to use, the DM01 replaces outdated circular paper chart recorders, providing efficient data management and improved process insight.
Monitoring pressure and vacuum in pharmaceutical autoclave sterilization cycles - Specialized pressure transmitters with integrated cooling elements handle the extreme temperatures and vacuum cycles of pharmaceutical autoclaves during sterile oncology drug production.
Vacuum transmitter for chlorine, hydrogen chloride and nitrogen oxide gas with NaOH solution - Capacitive ceramic sensor with PVDF and FFKM materials provides a stable vacuum measurement in gas scrubbers containing chlorine, HCl, and NOx, plus NaOH solution.
Vacuum drying pressure data logger - Digital vacuum recorder for a vacuum drying pilot process.- Low range vacuum pressure logger for 0 to -60 inH2O g - I am interested in monitoring vacuum on a pipeline in the field with a portable data logger.
Vacuum pressures in the range of a few millibars up to atmospheric pressure are easily measured by diaphragm based pressure measurement instrumentation. In this range of partial vacuum pressures it is common to measure the vacuum using either a negative gauge reference or an absolute reference pressure sensing device. The choice of a negative gauge or an absolute reference will depend on whether you are interested in measuring the pressure compared to atmospheric pressure or to a perfect vacuum.
High vacuum pressures are very close to zero absolute pressure and much harder to measure with diaphragm type instrumentation. At high vacuum pressures it is necessary to use different sensor technology which is based on ionisation or thermal conductivity measurement principles.
Vacuum measurement is critical across diverse industries and research fields. Users often include design engineers developing new equipment, installation engineers setting up vacuum systems, control and instrumentation engineers integrating sensors into automated processes, and maintenance engineers ensuring continued optimal performance. These professionals work in sectors like semiconductor manufacturing, where precise vacuum control is vital for fabrication processes; aerospace, where vacuum is used in altitude simulation and component testing; and pharmaceutical production, where vacuum is essential for sterilization and drying. Research laboratories also rely heavily on vacuum technology for experiments in physics, chemistry, and materials science. Geographically, these applications span the globe, wherever advanced manufacturing, research, or specialized processes requiring vacuum are conducted.
Questions & Answers
0 bar absolute = -1 bar gauge
Is zero bar absolute the same as minus 1 bar gauge?
No, only when atmospheric pressure happens to correspond exactly to 1 bar absolute which rarely happens.
Does 1 bar cover the vacuum range
Is a minus 1 bar range adequate for measuring over the vacuum range?
For most applications yes, especially if measuring low suction pressures. If measuring a very high vacuum to some degree of accuracy, it is best to measure with a positive absolute range, since a negative gauge device will give different readings due to the changes in atmospheric pressure.
Technology used to measure over vacuum range
What type of sensing technology is used for measuring in the vacuum range?
For vacuum ranges 0-100 mbar up to 0-1000 mbar absolute it is usual to use a lower cost strain gauge diaphragm type. For ranges from 0-1 mbar up to 0-1000 mbar absolute, capacitive or inductive sensing techniques are the typical methods for measuring higher vacuums more precisely and with less drift. For ultra high vacuum ranges below 0-1 mbar it is not possible to measure this low a pressure with electromechanical devices and it is necessary to use less direct methods such as thermal conductivity and ionisation techniques.
Vacuum units
What pressure units are used for measuring vacuum pressures?
Vacuum level variations in a pumped chamber
Will the vacuum level be the same at the opposite end to the suction end of a chamber where a vacuum pump is connected?
If there is flow of gas, then you should expect there to be some difference in pressure, but it will depend on flow rate, size of volume and any restrictions between pump and end of chamber. If the suction pressure is static with no flow, then the vacuum pressure will equalise it all points.
Vacuum Gauge vs Vacuum Absolute
What is difference between reading pressure in vacuum gauge and vacuum absolute?
Vacuum gauge is measured from ambient air pressure in the negative direction. So for example at ambient air pressure the vacuum reading is 0 bar gauge and if a suction pressure of 0.25 bar is applied, the vacuum reading will be -0.25 bar gauge.
Vacuum absolute is measured from a perfect vacuum in the positive direction. At ambient air pressure the vacuum reading will be the barometric air pressure, let’s use 1.015 bar absolute as an example. If a suction pressure of 0.25 bar is applied the vacuum reading will be 0.765 bar absolute.
Related Help Guides
- Measuring vacuum with negative gauge or absolute ranges
- What is the difference between vacuum and absolute pressure
- What does negative and positive gauge pressure mean
- Measuring negative pressure using a positive differential pressure range
- Measuring vacuum as a negative gauge pressure using a dp sensor
- Can you measure vacuum using a gauge pressure range
- Can you have a minus 20 psi gauge vacuum measurement range
- Measuring vacuum as an absolute range using a dp sensor
- Output signal orientation for a negative gauge pressure range
Related Technical Terms
Related Online Tools
Related Product and Application Guides
Related Application Questions and Answers
- Vacuum drying pressure data logger
- Low range vacuum pressure logger for 0 to -60 inH2O g
- High reading rate for measuring dynamic pressures to -200psf
- Using 25 mbar DP sensor on vacuum below 0.2 bar absolute
- Leak testing set for checking 1mb/min drop at negative 10 mbar vacuum
- Vacuum suction sensor & wall mount digital readout with switched contacts
- Vacuum pump inlet to outlet differential pressure sensor with 1500 Torr range
- Negative room pressure monitor and logger for multiple zones
- Vacuum digital gauge to measure 0 to 1000 mbar absolute
- 450 mmHg vacuum range pressure gauge
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