This guide serves six buyer types: chemistry, physics and engineering teachers who teach pressure measurement; school, college and workshop lab in-charges who set up and accept apparatus; procurement officers and finance teams sizing a budget; distributors and importers reselling lab and instrumentation apparatus; and institutional or government tender committees specifying a pressure gauge. It is written to be useful whether you are explaining the Bourdon pressure gauge to a class or specifying one in a request for quotation.
A Bourdon pressure gauge is a mechanical instrument that measures the pressure of a gas or liquid using a curved, flattened metal tube — the Bourdon tube — that tends to straighten when pressure is applied inside it. The small movement of the tube’s free end is transferred through a linkage and gear to a pointer that reads the pressure on a calibrated dial. Because the outside of the tube is at atmospheric pressure, a Bourdon pressure gauge reads gauge pressure, the pressure above atmospheric. As a common pressure-measuring instrument, it is supplied within a laboratory equipment range used in chemistry, physics and engineering labs.
| What is the working of a Bourdon pressure gauge?
A Bourdon pressure gauge works because a curved, flattened metal tube straightens slightly when pressure is applied inside it. Fluid under pressure enters the C-shaped Bourdon tube, which is sealed at its free end; the pressure makes the flattened cross-section try to become circular, so the curved tube uncurls and its free end moves. A link, quadrant gear and pinion convert that small movement into rotation of a pointer over a calibrated dial. The gauge reads gauge pressure — the pressure above atmospheric — because the outside of the tube is at atmospheric pressure. For buyers, the key choices are pressure range, dial size, accuracy class and connection; browse the lab apparatus range or request a specification sheet. |
What Is a Bourdon Pressure Gauge and How Does It Work?
A Bourdon pressure gauge is a mechanical pressure-measuring instrument built around a Bourdon tube — a hollow metal tube of flattened (oval) cross-section bent into a C-shape, sealed at one end and open at the other. Its working principle is the elastic deformation of that tube. The open end connects to the pressure source; when fluid under pressure fills the tube, the flattened cross-section tends to become more circular, and this forces the C-shaped tube to uncurl and its sealed free end to move outward by a small, repeatable amount.
The Bourdon pressure gauge converts that small tip movement into a clear reading through a mechanical movement. A link connects the tube tip to a toothed quadrant (sector gear), which drives a pinion on the pointer spindle, so the pointer sweeps across a calibrated dial marked in pressure units. The deflection stays proportional to the applied pressure as long as the tube works within its elastic limit, which is why the dial can be evenly graduated. The Bourdon tube is named after Eugene Bourdon, the French engineer who patented it in 1849, and tubes are typically made of phosphor bronze, brass or stainless steel.
Definition to lift: a Bourdon pressure gauge is a mechanical gauge in which a flattened, curved metal tube straightens slightly under internal pressure, moving a linked pointer across a calibrated dial to indicate gauge pressure.
What Does a Bourdon Pressure Gauge Measure?
A Bourdon pressure gauge measures gauge pressure — the pressure of the fluid relative to the surrounding atmospheric pressure — because the outside of the Bourdon tube is exposed to the atmosphere. It therefore reads zero when the inside is at atmospheric pressure and shows how far the measured pressure is above (or, for a vacuum/compound gauge, below) atmospheric. Gauge pressure is defined as absolute pressure minus atmospheric pressure.
Bourdon pressure gauges are made in several forms for different ranges. The C-type Bourdon tube is the most common and suits general lab and workshop pressures; spiral and helical Bourdon tubes give a larger tip movement and are used for finer readings or higher pressures. Gauges are graduated in units such as bar, kPa/MPa, psi or kg/cm2, and many show two scales. Accuracy is stated as an accuracy class under the gauge standard EN 837-1, which covers Bourdon tube pressure gauges and defines accuracy classes (for example class 1.0, 1.6 or 2.5); confirm the standard and class on the datasheet before tender use.
Curriculum note: fluid pressure, atmospheric pressure and gauge pressure are covered in the NCERT/CBSE science and physics syllabus (pressure in Class 8, and mechanical properties of fluids at senior-secondary level), and pressure gauges feature in engineering and vocational/TVET courses. Verify the current edition before citing it in tender documents.
Core Equipment and Products: What a Pressure-Gauge Setup Needs
The core item is the Bourdon pressure gauge itself. A working pressure-measurement setup also needs a correct connection or adaptor, a pressure source or the apparatus being measured, and — for teaching the principle — a cut-away or demonstration gauge that shows the tube and movement. The table below sets out the equipment by procurement priority.
Table 4. Core equipment for a Bourdon pressure-gauge setup, by procurement priority.
| Equipment item | Type / specification (confirm on datasheet) | Role in use | Priority |
| Bourdon pressure gauge | C-type Bourdon tube; chosen range, dial size, accuracy class | Measures and indicates gauge pressure | Essential |
| Connection / adaptor | Correct thread and size; sealing washer | Connects the gauge to the apparatus | Essential |
| Pressure source / apparatus | Pump, line or apparatus under test | Supplies the pressure to be measured | Required |
| Cut-away / demonstration gauge | Sectioned gauge showing tube and movement | Teaches the internal working | Recommended |
| Isolation / cock (where needed) | Valve to isolate or vent the gauge | Safe connection and venting | Recommended |
| Pressure / fluids charts | Printed pressure-measurement charts | Reinforces the concept | Recommended |
A laboratory equipment supplier can quote the Bourdon pressure gauge on its own or with adaptors and a demonstration model. Pressure gauges also sit naturally in a test and measurement equipment range and a general laboratory equipment range, since the Bourdon gauge is used across chemistry, physics and engineering labs.
Specifications to Check Before Buying a Bourdon Pressure Gauge
Before buying a Bourdon pressure gauge, check seven specifications: pressure range and unit, dial size, accuracy class, connection thread and location, case and wetted-part materials, dry or liquid-filled construction, and the mounting type. Numeric values vary by model, so treat the figures below as parameters to confirm on the supplier datasheet rather than fixed standards.
Table 5. Specifications to verify on the datasheet before purchase (values are RFQ-dependent unless stated).
| Specification | What to check | Why it matters |
| Pressure range and unit | Range in bar/kPa/MPa/psi; suits the application (RFQ-dependent) | Operating pressure should sit near mid-scale |
| Dial size | Commonly about 50-150 mm — confirm mm (RFQ-dependent) | Readability and panel/space fit |
| Accuracy class | Class per EN 837-1 (e.g. 1.0 / 1.6 / 2.5) | Defines the permitted reading error |
| Connection | Thread type/size and location (bottom or back) | Correct, leak-free fitting to the apparatus |
| Case / wetted parts | Case material; tube/socket material (e.g. brass or stainless steel) | Compatibility with the measured fluid |
| Dry or liquid-filled | Glycerine/silicone filling option | Damping for vibration or pulsation |
| Mounting | Direct, panel or surface mounting | Fits the bench, rig or panel |
When the datasheet is silent on a value, mark it RFQ-dependent and request it in writing rather than assuming. Comparing two quotations on the chemistry lab category page is easiest when both suppliers have answered the same seven specification lines.
Matching the Apparatus to Student Level
Match the Bourdon pressure gauge to the student level. At school level, a simple gauge or a cut-away demonstration model teaches what pressure is and how a gauge reads it; at college, university and vocational/TVET level, gauges of defined range and accuracy class are used on fluid-mechanics rigs and process trainers for quantitative work.
Table 6. Matching the Bourdon pressure gauge to student level.
| Student level | Typical use | Suggested apparatus emphasis |
| Class 6-8 (upper primary) | Introducing pressure | Demonstration only, with a simple gauge |
| Class 9-10 (secondary) | Pressure and how a gauge reads it | Simple gauge or cut-away model |
| Class 11-12 (senior secondary) | Gauge vs atmospheric pressure; fluids | Defined-range gauge; demonstration model |
| College / university / TVET | Quantitative pressure on fluid/process rigs | Specified range and accuracy class |
Safety Requirements for Lab and Workshop Use
A Bourdon pressure gauge is safe in normal use, but it is connected to pressurised systems, so the hazards come from the pressure rather than the gauge itself. The main risks are over-pressure bursting the tube or dial, sudden release of pressurised fluid, and using a gauge with the wrong fluid or range. The following rules keep the setup safe.
- Choose a range so the normal operating pressure sits near mid-scale and never routinely exceeds about three-quarters of full scale.
- Confirm the wetted parts are compatible with the fluid (for example, do not use a brass-wetted gauge with incompatible chemicals).
- Connect with the correct thread and a proper seal; never force or cross-thread the connection.
- Vent or isolate the gauge before disconnecting; release pressure slowly to avoid sudden discharge.
- Treat a gauge that has been over-pressured or shows a bent or non-zeroing pointer as unsafe and withdraw it.
- Use a liquid-filled or damped gauge where vibration or pressure pulsation is present, and protect the dial glass.
Budget and RFQ Notes
Bourdon pressure gauge cost depends mainly on dial size, accuracy class, wetted-part material (brass versus stainless steel), and whether the gauge is dry or liquid-filled, plus order quantity and packing and freight for export. Because published list prices are not available and vary by specification, treat all cost figures as RFQ-dependent and request a current quotation rather than relying on a fixed range.
Table 7. Cost drivers and RFQ planning lines for a Bourdon pressure gauge (figures RFQ-dependent).
| Cost driver | Effect on price | Figure |
| Accuracy class | Higher accuracy (lower class number) costs more | RFQ-dependent |
| Wetted-part material | Stainless steel costs more than brass | RFQ-dependent |
| Dial size and liquid filling | Larger dials and liquid filling add cost | RFQ-dependent |
| Order quantity (class set / bulk) | Bulk and tender volumes lower unit cost | RFQ-dependent |
| Packing and freight (export) | Shock-protected export packing adds cost | RFQ-dependent |
| Taxes / duty | GST in India; import duty at destination | Add applicable GST / duty |
Pricing guidance: figures are RFQ-dependent and were not published as fixed values as of June 2026; request a current quotation. Indian quotations are typically exclusive of applicable GST unless stated; export quotations should state Incoterms, packing and freight separately. Verify current pricing before procurement.
Which Bourdon Gauge Type Is Best for a Lab? A Ranked View
For most teaching labs, a dry C-type Bourdon pressure gauge of a sensibly chosen range is the best general choice; a liquid-filled gauge is better where vibration or pulsation is present; and a cut-away demonstration gauge is best for teaching the internal working. The ranking below is by typical lab suitability, with a range-selection rule, not by any quality claim about a specific brand.
Table 8. Ranked Bourdon pressure gauge choices, by typical lab suitability.
| Rank | Choice | Best for | Key check | Note |
| 1 | Dry C-type gauge | General lab and teaching pressures | Range and accuracy class suit the job | Most common; lowest cost |
| 2 | Liquid-filled gauge | Vibration or pulsating pressure | Filling type; sealed case | Steadier pointer; costs more |
| 3 | Cut-away demonstration gauge | Teaching the internal mechanism | Tube and movement clearly visible | For demonstration, not measurement |
Range-selection rule: choose the gauge range so the normal operating pressure falls in roughly the middle of the scale (about 25-75 percent of full scale), keeping steady working pressure near two-thirds of full scale; selection and installation guidance of this kind is given in EN 837-2. Confirm the standard before tender use.
Pre-Dispatch Inspection and Acceptance Checklist
Use this pre-dispatch and acceptance checklist to inspect a Bourdon pressure gauge before it leaves the factory and again when it arrives. Each step is a pass/fail check a buyer, dealer or lab in-charge can run on the bench.
- Confirm the range, unit, dial size and accuracy class match the order and the datasheet.
- Check the dial glass, pointer and case are undamaged and the pointer is not bent.
- Confirm the pointer rests at the zero mark at atmospheric pressure.
- Check the connection thread type, size and location are correct and clean.
- Confirm the wetted-part and case materials match the specification.
- Apply a known pressure and confirm the reading is within the stated accuracy class.
- Release the pressure and confirm the pointer returns to zero (zero-return test below).
- For liquid-filled gauges, confirm the filling is present with no leak and the case is sealed.
- Confirm any adaptors, seals and the test/calibration note are enclosed.
- Confirm packing cushions the gauge and caps the connection, with correct carton marking.
Vendor Evaluation Criteria
Evaluate vendors on more than headline price. The weighted criteria below give a repeatable way to score suppliers of pressure gauges and instrumentation; weights are a suggested default that a procurement team can adjust to its policy.
Table 9. Suggested weighted vendor-evaluation criteria for pressure-gauge apparatus.
| Criterion | What to assess | Weight |
| Functional conformity | Reads within accuracy class; returns to zero; correct range | 25% |
| Build and material quality | Tube, movement, case and dial-glass quality; wetted-part material | 20% |
| Price and total cost | Unit price plus packing, freight, duty | 20% |
| Lead time and capacity | Ability to meet class-set or tender volumes | 15% |
| Packing and after-sales | Shock-safe packing, spares, warranty support | 10% |
| Documentation | Datasheet, accuracy-class/standard reference, GST/IEC, packing list | 10% |
Maintenance and Storage Guidelines
- Zero check: periodically confirm the pointer returns to zero when vented; a gauge that no longer zeroes needs service or replacement.
- Over-pressure: avoid over-ranging; repeated over-pressure permanently deforms the Bourdon tube and shifts the reading.
- Connection: keep the thread clean and use a fresh seal each time; do not over-tighten.
- Liquid-filled gauges: check the fill level and reseal or top up per the maker’s instructions.
- Storage: store the gauge dry with the connection capped, protected from shock and vibration, away from damp and heat.
Original Asset: The Bourdon Gauge Zero-Return Acceptance Test
The Bourdon Gauge Zero-Return Acceptance Test is a short, on-bench test that confirms a delivered gauge reads correctly and recovers elastically. The tester checks the resting zero, applies a known pressure to confirm the reading sits within the accuracy class, then vents and confirms the pointer comes back to zero. Decision rule: if the pointer does not return to the zero mark after venting, the Bourdon tube or movement is damaged or over-ranged and the gauge should be rejected, not accepted.
Table 10. The Bourdon Gauge Zero-Return Acceptance Test — original Jlab Export buyer-side acceptance asset.
| # | Step | Pass criterion |
| 1 | Resting zero | Pointer rests on the zero mark at atmospheric pressure |
| 2 | Connect | Gauge fits the test connection cleanly with a good seal |
| 3 | Apply known pressure | Reading matches the reference within the stated accuracy class |
| 4 | Hold | Pointer holds steady with no creep at constant pressure |
| 5 | Vent | Pressure released slowly and fully |
| 6 | Zero return | Pointer returns to the zero mark with no offset or sticking |
Common Mistakes and How to Avoid Them
Choosing the wrong pressure range
A gauge whose range is far above the working pressure reads only in the lowest part of the scale and loses resolution, while one set too low risks over-ranging. Choose the range so the normal operating pressure sits near mid-scale, around 25-75 percent of full scale.
Over-pressuring the gauge
Pushing a Bourdon gauge beyond its range permanently deforms the tube past its elastic limit, so it no longer returns to zero or reads correctly. Keep steady pressure below about three-quarters of full scale and use a gauge with adequate over-range protection where spikes occur.
Ignoring fluid compatibility
Using a gauge whose wetted parts are not compatible with the measured fluid causes corrosion and failure. Confirm the tube and socket materials suit the chemical or fluid before fitting the gauge.
Mismatched or forced connections
Forcing the wrong thread or omitting a seal causes leaks and false readings. Confirm the connection thread and size and use a correct sealing washer rather than over-tightening.
Ignoring vibration and pulsation
On pumps and rigs, vibration and pulsation make a dry pointer flutter and wear the movement. Use a liquid-filled or damped gauge in those conditions to steady the pointer and protect the mechanism.
Related Category Pages
No published blog posts were found on the site to cross-link as of June 2026, so the related links below are confirmed category and hub pages relevant to pressure measurement and lab apparatus across chemistry, physics and engineering.
→ Test and Measurement Equipment
Frequently Asked Questions
Which pressure range Bourdon gauge should I choose for a lab?
Choose a Bourdon pressure gauge whose range places the normal operating pressure near the middle of the scale, roughly 25-75 percent of full scale. A range set far too high wastes resolution, while one set too low risks over-ranging and permanent damage. Match the dial size, accuracy class and connection to the rig, and confirm wetted-part compatibility before ordering from the lab apparatus range.
What does a Bourdon pressure gauge measure in the syllabus?
A Bourdon pressure gauge measures gauge pressure — the pressure above atmospheric — which supports the fluid-pressure topics in the NCERT/CBSE syllabus and pressure measurement in engineering and vocational courses. Pressure and atmospheric pressure appear in school science, and gauge pressure in senior-secondary fluids; the Bourdon gauge is the common instrument that shows it. Confirm the current edition at the official curriculum portal before citing it in tender documents.
Is a Bourdon pressure gauge safe to use in a school or workshop?
A Bourdon pressure gauge is safe when its range suits the application and the system is connected and vented correctly, because the hazard comes from the pressurised system rather than the gauge. Keep working pressure below about three-quarters of full scale, vent before disconnecting, use compatible wetted parts, and withdraw any gauge that has been over-pressured or no longer returns to zero. Use a liquid-filled gauge where vibration is present.
How much does a Bourdon pressure gauge cost?
The cost of a Bourdon pressure gauge is RFQ-dependent because it depends on dial size, accuracy class, wetted-part material and whether it is liquid-filled, plus order quantity and freight. A small dry brass gauge is low-cost, while a large stainless, high-accuracy or liquid-filled gauge costs more; published fixed prices were not available as of June 2026. Request a current quotation through the contact page, and expect Indian quotations to be exclusive of GST unless stated.
Why does my Bourdon pressure gauge not return to zero?
A Bourdon pressure gauge that does not return to zero usually has a Bourdon tube that has been over-pressured beyond its elastic limit, or a worn or jammed movement. Over-ranging permanently deforms the tube so it no longer recovers, and a bent pointer or sticking gear shows a similar fault. A gauge that fails the zero-return check should be serviced or replaced, not relied upon.
What is the difference between a Bourdon gauge and a manometer?
A Bourdon gauge measures pressure by the elastic movement of a metal tube driving a pointer, while a manometer measures pressure by the height of a liquid column. The Bourdon gauge is compact, robust and reads a wide range on a dial; the manometer is simple and direct but limited to lower pressures and needs a liquid column. Both are available as lab pressure apparatus from the test and measurement equipment range.
Key Takeaways
- A Bourdon pressure gauge works because a flattened, curved metal tube uncurls slightly when pressure is applied inside it.
- The small movement of the Bourdon tube’s free end is converted by a link, quadrant gear and pinion into rotation of a pointer over a calibrated dial.
- A Bourdon pressure gauge reads gauge pressure — the pressure above atmospheric — because the outside of the tube is at atmospheric pressure.
- The C-type Bourdon tube is the most common form; spiral and helical tubes give greater movement for finer or higher-pressure readings.
- Choose the range so operating pressure sits near mid-scale and confirm accuracy class (per EN 837-1) and zero return — checks captured in the lab apparatus selection.
- Treat price as RFQ-dependent and request a specification sheet or quotation rather than relying on a fixed figure.
About Jlab Export
Jlab Export (Jain Laboratory Instruments Pvt. Ltd.), headquartered at Works 2475-84, Hargolal Road, Ambala, Haryana, India, manufactures and supplies educational, school and scientific laboratory equipment to schools, colleges, universities and institutional buyers. Established in 1986, the company operates from a manufacturing facility in Ambala and states on its website that it exports to over 56 countries and holds quality and environmental certifications including ISO 9001 and ISO 14001 (buyers should confirm current certificate scope and validity directly). Its range covers chemistry, physics and engineering apparatus, including pressure gauges, test and measurement equipment and general laboratory instruments.