Baumer Authorized Dealer in India · Data Sheet 31-08-12
Baumer CA Model — Gas Filled Industrial Thermometer, Filled System
An inert gas-filled expansion thermometer built to EN 13190, offering everything the CB bimetal model does, plus one key advantage: a capillary connection that lets you mount the dial up to 15 metres away from the sensing point. All-stainless construction, optional silicon oil filling, and optional CE/ATEX electrical contacts for alarm or interlock duty.
Product Overview
What Is the Baumer CA Gas Filled Temperature Gauge?
The Baumer CA Model is a stainless steel industrial thermometer built to EN 13190, using an inert gas-filled expansion system rather than a bimetal strip to sense temperature. A sealed sensing bulb, capillary tube and Bourdon tube — all charged with inert gas — form a closed pressure system: as the bulb's temperature changes, the gas pressure inside changes proportionally, and that pressure change is what drives the pointer.
The practical benefit of this design is remote indication. Because the sensing bulb and the display dial are connected only by a flexible capillary — available up to 15 metres — the CA Model can be installed with its sensing point deep inside a furnace, on an inaccessible vessel, or high on a structure, while the dial itself sits at eye level where an operator can actually read it. A bimetal thermometer like the Baumer CB Model cannot do this, since its dial is mechanically fixed to the sensing stem.
Like its bimetal counterpart, the CA Model requires no external power, wiring, or electronics — it is a fully mechanical instrument, which means no calibration drift from ageing electronic components and no risk of losing the reading during a power interruption. This makes it a dependable choice anywhere local or remote-but-mechanical temperature indication is preferred over an electronic transmitter loop.
Not sure whether you need a rigid-stem or capillary CA Model configuration? Send us your installation sketch.
Talk to a Technical ExpertGas Filled vs. Bimetal — Quick Distinction
Why Choose Gas-Filled Over Bimetal?
Both the CA and CB models meet EN 13190 Class 1 accuracy and share an all-stainless-steel build — the deciding factor between them is almost always whether you need the dial located away from the sensing point.
| Factor | CA — Gas Filled | CB — Bimetal |
|---|---|---|
| Sensing element | Gas-filled bulb, capillary & Bourdon tube | Coiled bimetal strip in the stem |
| Dial location | Local or remote (up to 15m via capillary) | Fixed at the stem/sensing point |
| Best for | Inaccessible, high, or hazardous-to-approach sensing points | Directly accessible pipe/vessel connections |
| Relative complexity | Slightly more complex sealed system | Simpler mechanical construction |
| Electrical contact option | Available (NS100/150mm) | Not covered on CB Model |
Key Features
What Makes the CA Model a Dependable Remote-Indication Instrument
Inert Gas Filled Expansion System
Sealed gas system drives the pointer with no direct mechanical link needed between bulb and dial.
Stainless Steel Case
AISI 304 SS bayonet-type case for corrosion resistance and easy field servicing.
Stainless Steel Stem
AISI 316 SS stem and connection, TIG Argon Arc welded for a rugged, corrosion-resistant joint.
EN 13190 Standard
Manufactured and scale-graduated to the European filled-system thermometer standard.
Class 1 Accuracy
Meets EN 13190 Class 1 — the tightest tolerance band defined for this instrument type.
Silicon Oil Filled (Optional)
Option QA dampens dial vibration on installations near pumps or rotating machinery.
Optional Thermowell
Allows bulb removal for calibration or replacement without a process shutdown.
Bottom Entry
Type 2/3 mounting for vertical or lower-back pipe and vessel connections.
Back Entry
Type 5 mounting with front flange for panel-style installation.
Every Angle Entry
Type 8 mounting rotates the dial independent of stem orientation.
Remote Reading with Capillary
Type A2 configuration with capillary lengths up to 15 metres for distant dial placement.
Suitable for High & Low Temperatures
Standard ranges span -100°C to +650°C across the available nominal range table.
Corrosion Resistant Construction
All-SS wetted parts suit chemical, food, pharma, pulp, paper and refinery environments.
No External Power Required
Fully mechanical gas-expansion system needs no wiring or power supply.
Long Service Life
Sealed IP65 construction protects the movement from dust and moisture over years of use.
IP65 Protection
Dust-tight and splash-resistant as standard; IP55 on the electrical contact version.
Optional Electrical Contacts
CE & ATEX approved contacts for NS100/150mm, in single or double NO/NC configurations.
Suitable for Vibrating Applications
Silicon-oil-filled version recommended near pumps, compressors and rotating equipment.
Technical Data
CA Model — Full Technical Data
Specifications as per Baumer datasheet 31-08-12. Zebco Engineering can configure any combination below for your application.
| Parameter | Specification |
|---|---|
| Measuring principle | Inert gas-filled expansion system |
| Dial size (NS) | 100, 125, 150, 200, 250 mm |
| Standard | EN 13190 |
| Accuracy | Class 1 as per EN 13190 |
| Ambient temperature | -25°C to +65°C |
| Operating pressure | 15 kg/cm² (without thermowell) |
| Overrange limit | 120% of full scale |
| Stem diameter | 8 mm (standard) — 6, 6.35, 9.5, 10, 12 mm optional |
| Stem length | Below-thread max. 600 mm |
| Capillary length | Up to 15 metres (type A2, capillary version) |
| Case material | AISI 304 SS (bayonet type) |
| Stem material | AISI 316 SS |
| Window material | Sheet glass (standard) · Plexi glass (silicon-oil-filled) · Polycarbonate dome (electrical contacts) |
| Protection rating | IP 65 (IP 55 with electrical contacts) |
| Process connection | ½" BSP (M), Adjustable (standard) |
| Thread type | Adjustable (ZI, standard), Fixed (ZJ), Revolving/Swivel (KJ) |
| Mounting type | Wall/surface/projection, direct bottom entry, direct lower back entry, lower back entry with front flange, every angle back entry, lower back entry with mounting bracket |
| Joints | TIG Argon Arc welding |
| Dial | Aluminium, black graduation on white background |
| Pointer | Aluminium, black, micrometer zero adjustable |
| Gasket & filling plug | Neoprene (standard) · Viton (silicon-oil-filled) |
| Approvals | GOST-R (option); CE & ATEX for electrical contacts |
| Optional accessories | Thermowell, custom dial, SS tag plate, calibration certificate, material test certificate |
Silicon-Oil-Filled Version
| Parameter | Specification |
|---|---|
| Accuracy | Class 1 as per EN 13190 |
| Ambient temperature | Maximum 65°C |
| Window | Plexi glass |
| Dampening liquid | Silicon oil (option QA) |
| Gasket & filling plug | Viton |
Electrical Contacts Version
| Parameter | Specification |
|---|---|
| Accuracy | Class 1 as per EN 13190 |
| Ambient temperature | Maximum 65°C |
| Window | Polycarbonate dome |
| Dampening liquid | Dielectric oil (optional) |
Note: adding mechanical electrical contacts affects instrument accuracy — e.g. 1% becomes 1.5%, 1.6% becomes 2.4% (add 50% of base accuracy). For magnetically-assisted contacts, this addition cannot be applied within ±5% of the set point.
Nominal Ranges
Nominal Range, Measuring Range & Error Limits (per EN 13190)
| Nominal Range (°C) | Measuring Range (°C) | Limit of Error (±°C) |
|---|---|---|
| -20 to +40 | -10 to +30 | 1 |
| -20 to +60 | -10 to +50 | 1 |
| -20 to +120 | -10 to +110 | 2 |
| -30 to +30 | -20 to +20 | 1 |
| -30 to +50 | -20 to +40 | 1 |
| -30 to +70 | -20 to +60 | 1 |
| -40 to +40 | -30 to +30 | 1 |
| -40 to +60 | -30 to +50 | 1 |
| -100 to +60 | -80 to +40 | 2 |
| 0 to 60 | 10 to 50 | 1 |
| 0 to 80 | 10 to 70 | 1 |
| 0 to 100 | 10 to 90 | 1 |
| 0 to 120 | 10 to 110 | 2 |
| 0 to 160 | 20 to 140 | 2 |
| 0 to 200 | 20 to 180 | 2 |
| 0 to 250 | 30 to 220 | 2.5 |
| 0 to 300 | 30 to 270 | 5 |
| 0 to 400 | 50 to 350 | 5 |
| 0 to 500 | 50 to 450 | 5 |
| 0 to 600 | 100 to 500 | 10 |
Additional positive ranges up to 0/650°C and compound ranges as low as -80/60°C are available — see the full range table. Compound ranges are not recommended with the electrical contact option. °F and dual °C/°F scales available on request.
Available Variants
Direct Mount, Remote Mount & Mounting Options
Rigid Stem vs. Capillary Version
Direct Mount — Rigid Stem
Dial mounts directly at the process connection, identical in layout to the CB bimetal thermometer. Choose this when the sensing point is easily viewable and accessible.
Remote Mount — Capillary Version
Sensing bulb installs at the process point; the dial connects via a flexible capillary (up to 15 m) routed to a convenient viewing or panel location.
PE (304 SS) / PG (316 SS)
Capillary tubing material selection, with optional armoured covering in 304 SS, 316 SS, or PVC (ambient max. 60°C) for mechanical protection against abrasion or crushing.
Mounting Types
| Type | Description | Best Suited For |
|---|---|---|
| Type 1 | Wall / Surface / Projection Mounting — Bottom Entry | Capillary version, dial wall-mounted independent of the sensing point |
| Type 2 | Direct Bottom Entry | Vertical pipe or top-entry tank connection, rigid stem |
| Type 3 | Direct Lower Back Entry | Horizontal pipe run, dial viewed face-on |
| Type 5 | Lower Back Entry with Front Flange | Panel-mounted capillary installations |
| Type 8 | Every Angle Back Entry | Dial angle needs to be independent of stem / capillary routing |
| Type 9 | Lower Back Entry with Mounting Bracket | Remote panel mounting with capillary loop and bracket support |
Types 2, 3, and 8 are available in both direct mount (Type A1) and capillary (Type A2) versions. Types 1, 5, and 9 are intended for capillary (Type A2) installations where the dial is mounted remotely from the sensing point.
Process Connection & Stem Diameter
| Code | Connection | Max Stem Diameter |
|---|---|---|
| 3BM / 3NM / 3TM | 3/8" BSP(M) / NPT(M) / BSPT(M) | Suitable for stem diameter 6–10 mm |
| 4BM / 4NM / 4TM | 1/2" BSP(M) (standard) / NPT(M) / BSPT(M) | Suitable for stem diameter 6–10 mm |
| 5BM | 3/4" BSP(M) | Suitable for stem diameter 6–10 mm |
| 4MM | M20 x 1.5 (M) | Suitable for stem diameter 6–10 mm |
NPT and BSPT variants are not recommended for revolving/swivel connections. Metric, PT, PF, flared, UNF, G or R connections available on request.
Working Principle
How the CA Model's Gas Expansion System Works
Five steps take you from process temperature to pointer reading — understanding each helps when explaining installation or troubleshooting requirements to site teams.
Gas Expansion Principle
The sensing bulb, capillary and Bourdon tube form one sealed system, pre-charged with an inert gas at the factory.
Temperature Sensing
The bulb, immersed in the process media, reaches process temperature and the gas inside expands or contracts accordingly.
Pressure Transmission
The resulting gas pressure change transmits instantly through the capillary tube to the Bourdon tube in the dial housing.
Bourdon Tube Movement
The Bourdon tube uncoils or curls proportionally to the internal gas pressure, converting pressure into mechanical rotation.
Pointer Indication
A geared movement converts the Bourdon tube's rotation into pointer travel across the graduated dial scale.
Industrial advantage: because the whole system is a sealed, factory-charged unit, there is nothing to recalibrate electronically — the main installation consideration is simply protecting the capillary from kinking, crushing, or excessive tight-radius bends during routing.
Applications
Where the CA Model Is Used
Boilers
Furnace and flue-gas temperature indication where the sensing point sits deep inside hot, inaccessible zones.
Heat Exchangers
Inlet/outlet temperature monitoring with the dial mounted for easy panel viewing.
Steam Pipelines
Header temperature indication, capillary routed to accessible viewing height.
Chemical Reactors
Vessel temperature with remote dial placement away from hazardous or hot zones.
Storage Tanks
Bulk liquid temperature monitoring on tall or elevated tanks with ground-level dial reading.
Distillation Columns
Column temperature indication where the sensing point is at height and the dial is panel-mounted below.
Furnaces
High-temperature zone monitoring with the dial kept away from radiant heat exposure.
Compressors
Discharge temperature indication with silicon-oil-filled version for vibration resistance.
HVAC Systems
Chilled/hot water loop temperature indication with flexible dial placement.
Food Processing
Corrosion-resistant construction suited to wash-down and hygienic process areas.
Water Treatment
Process and effluent temperature monitoring across treatment stages.
Pharmaceutical Equipment
Clean, all-SS construction for process and utility temperature indication.
Industries Served
Industries That Rely on the Baumer CA Model
Oil & Gas
Remote dial placement for pipeline and separator temperature indication in hazardous zones.
Chemical
Corrosive process stream monitoring with dial mounted away from the process point.
Petrochemical
High-temperature column and reactor indication with capillary remote reading.
Power Plants
Furnace and boiler temperature indication where direct-mount access is impractical.
Steel
Furnace zone temperature monitoring kept away from extreme radiant heat.
Cement
Kiln-adjacent temperature indication with dial mounted at a safe viewing distance.
Mining
Remote indication for equipment installed in inaccessible or hazardous locations.
Pharmaceutical
Clean, corrosion-resistant indication for process and utility temperature monitoring.
Food & Beverage
Hygienic-compatible construction for bottling, brewing and processing lines.
Sugar
Boiling house temperature indication with remote dial for operator convenience.
Paper
Digester temperature monitoring resistant to pulp and bleaching chemicals.
Textile
Dye bath and steam line temperature indication in wet-processing areas.
Marine
Engine room temperature indication resistant to vibration and salt-air corrosion.
HVAC
Remote dial placement for chilled/hot water loop indication in building systems.
OEM Machinery
Capillary version for skid packages where the sensing point is buried within the machine frame.
Water Treatment
Process temperature monitoring across treatment stages with flexible panel mounting.
Renewable Energy
Biogas and solar-thermal loop temperature indication with remote-mounted dials.
Advantages
Why the CA Model Is Specified for Remote Indication
Accurate Remote Temperature Measurement
Capillary transmission maintains Class 1 accuracy at the dial regardless of distance from the bulb.
Suitable for Long Distance Indication
Capillary lengths to 15 metres bring the dial to wherever the operator actually stands.
Excellent Vibration Resistance
The dial can be isolated from a vibrating sensing point entirely via the capillary run.
Long Mechanical Life
Sealed gas system with no electronic components to degrade over time.
High Reliability
Factory-charged, sealed measuring chain with a proven mechanical design.
No Power Supply Required
Fully mechanical operation independent of plant electrical infrastructure.
Easy Installation
Threaded process connection and straightforward capillary routing.
Low Maintenance
No batteries or electronics; periodic visual and zero-point checks are typically sufficient.
Rugged Industrial Design
All-SS, TIG-welded construction built for continuous plant-floor duty.
Comparison Tables
How the CA Model Compares
Baumer CA vs. Baumer CB
| Factor | CA — Gas Filled | CB — Bimetal |
|---|---|---|
| Sensing method | Gas-filled bulb, capillary, Bourdon tube | Coiled bimetal strip |
| Remote dial capability | Yes, up to 15 m capillary | No — dial fixed at stem |
| Dial sizes available | 100–250 mm | 50–150 mm |
| Electrical contact option | Available (NS 100 / 150 mm) | Not specified on datasheet |
| Typical use case | Remote / inaccessible sensing points | Directly accessible pipe / vessel connections |
Gas Filled vs. Digital Temperature Indicator
| Factor | CA — Gas Filled | Digital Indicator |
|---|---|---|
| Power requirement | None | Battery or external power required |
| Remote reading method | Mechanical capillary transmission | Electronic cable or wireless signal |
| Data logging / alarm output | Only via optional electrical contacts | Typically standard on digital models |
| Best suited for | Simple, powerless remote indication | Applications needing data logging or network integration |
Remote Reading vs. Direct Reading
| Factor | Remote (Capillary, Type A2) | Direct (Rigid Stem, Type A1) |
|---|---|---|
| Installation complexity | Requires capillary routing and protection | Simple threaded installation |
| Viewing convenience | Dial placed wherever needed | Dial fixed at the process connection |
| Best suited for | High, hazardous, or inaccessible sensing points | Easily accessible pipe or vessel taps |
Electric Contacts
CE & ATEX Approved Electrical Contact Configurations
Available for NS 100mm and 150mm dial sizes only, with ingress protection up to IP 55 and a polycarbonate dome window. Compound ranges are not recommended with this option.
A) Single Insulated Magnetic Snap-Action Type (230V AC, 1A / 48V DC, 0.5A)
| Code | Configuration |
|---|---|
| RJ | Single, normally closed (1 NC) |
| RL | Single, normally open (1 NO) |
| RK | Double, normally closed + normally open (1 NC + 1 NO) |
| RM | Double, normally open + normally closed (1 NO + 1 NC) |
| RN | Double, normally closed (both NC) |
| RO | Double, normally open (both NO) |
| RU | Booster with relay for current up to 5 Amp |
B) Inductive Type (220V AC, 0.4 Amp)
| Code | Configuration |
|---|---|
| YW | Single, normally open (1 NO) |
| YV | Single, normally closed (1 NC) |
| YX | Double, normally closed + normally open (1 NC + 1 NO) |
| ZA | Double, normally open + normally closed (1 NO + 1 NC) |
| YY | Double, normally open (both NO) |
| YZ | Double, normally closed (both NC) |
For double insulated electrical contacts, consult the factory for price and delivery. Dampening liquid (dielectric oil) is optional on the electrical contact version.
Selection Guide
How to Configure Your CA Model Order
1. Dial Size
Match dial size to viewing distance and required electrical contact compatibility.
- Standard process indication: 100–150 mm
- Distant panel viewing: 200–250 mm
- Electrical contacts only available on 100mm and 150mm dials
2. Temperature Range
Select a nominal range where expected operating temperature sits within the middle third of the scale.
- Utility/ambient lines: 0–100°C or 0–120°C
- Process heat: 0–300°C to 0–650°C
- Sub-zero applications: -100 to +60°C compound range
3. Stem Length
Stem must achieve full immersion depth into the process stream, not just reach the pipe wall.
- Minimum immersion lengths vary by stem diameter — refer to the minimum stem length table (110–130mm depending on diameter)
- Confirm thermowell insertion length if used
4. Capillary Length
Specify only the length actually needed for the routing path — excess capillary adds cost and installation complexity.
- Short-distance remote mount: 1.5–3 metres
- Elevated or distant panel mount: up to 15 metres
- Specify armoured covering if the capillary route crosses walkways or exposed areas
5. Mounting Type
Choose based on whether the installation is direct-mount or capillary remote-mount.
- Direct, vertical pipe: Type 2
- Direct, horizontal pipe: Type 3
- Remote panel/wall mount: Type 1, 5 or 9
6. Thermowell & Process Connection
Confirm process tap size and whether a thermowell is required for isolation.
- Standard tap: ½" BSP(M) adjustable
- High-pressure or serviceable lines: specify a thermowell
- Revolving connections: use process connection type KJ
Installation & Maintenance
Getting Reliable Readings From Your CA Model
Proper Mounting
Select the mounting type that lets the dial face the normal operator viewing position, whether direct or capillary-remote.
Thermowell Installation
Fit and torque the thermowell before commissioning; confirm the bulb seats fully for accurate heat transfer.
Capillary Routing
Route the capillary with generous bend radii, secure it along its path, and avoid routing through high-traffic or pinch-point areas.
Avoiding Mechanical Damage
Never kink, crush, or forcibly straighten the capillary — armoured covering is recommended in exposed walkway or machinery areas.
Calibration Checks
Verify zero-point accuracy against a reference thermometer periodically, particularly after any mechanical disturbance to the capillary run.
Maintenance Best Practices
Inspect the window and dial for damage, check thermowell tightness at turnarounds, and confirm capillary routing remains undamaged during plant maintenance work.
Why Buy From Zebco Engineering LLP
Your Authorized Source for Genuine Baumer CA Model Thermometers
Genuine Baumer Products
Authorized dealer supply with full manufacturer traceability.
Technical Selection Support
Configuration review against your installation sketch before quotation.
Competitive Pricing
Transparent quotations with volume pricing for bulk and repeat orders.
Bulk Project Supply
Coordinated multi-item, multi-delivery supply for plant turnarounds and expansions.
Fast Delivery
Stocked common configurations dispatch quickly for urgent maintenance needs.
Export Documentation
Full export documentation, commercial invoicing and compliance packs for international orders.
Pan India Supply
Reliable dispatch to every major industrial cluster across India.
OEM Support
Recurring supply agreements and custom dial/branding for machine builders.
After-Sales Assistance
Calibration guidance and technical troubleshooting support after delivery.
Downloads
CA Model Reference Documents
Request any of the following documents alongside your enquiry.
Frequently Asked Questions
CA Model — Technical FAQ
An inert gas-filled expansion thermometer built to EN 13190, using a sealed sensing bulb, capillary and Bourdon tube system, available with a rigid stem or remote capillary reading up to 15 metres.
The CB Model is bimetal with the dial fixed at the sensing point; the CA Model is gas-filled and can place the dial up to 15 metres away via capillary.
Temperature at the sensing bulb changes the pressure of the sealed inert gas system, which is transmitted through the capillary to a Bourdon tube that drives the pointer.
100mm, 125mm, 150mm, 200mm and 250mm.
Class 1 per EN 13190.
Up to 15 metres, specified in the order code to the nearest 0.5 metre.
AISI 304 SS (code PE) or AISI 316 SS (code PG), with optional armoured covering in 304 SS, 316 SS, or PVC (ambient max. 60°C).
No — it is a fully mechanical, gas-expansion-driven instrument.
AISI 304 SS bayonet-type case and bezel; AISI 316 SS stem and connection, TIG Argon Arc welded.
½" BSP(M), adjustable, as standard; other BSP, NPT, BSPT and metric threads available.
Wall/surface/projection mounting (Type 1), direct bottom entry (Type 2), direct lower back entry (Type 3), lower back entry with front flange (Type 5), every angle back entry (Type 8), and lower back entry with mounting bracket (Type 9).
15 kg/cm², the maximum operating pressure when the sensing bulb is installed directly into the process without a thermowell.
It allows the sensing bulb to be removed for calibration or replacement without interrupting the process, and protects it from direct pressure and flow exposure.
IP 65 standard; IP 55 on the electrical contact version.
Yes, for NS 100mm and 150mm dials only, CE and ATEX approved, in single insulated magnetic snap-action or inductive type configurations.
Compound ranges are not recommended for the electrical contact option per the manufacturer's guidance.
Base accuracy is reduced — for example 1% becomes 1.5%, 1.6% becomes 2.4% (add 50% of base accuracy); magnetically-assisted contacts cannot have this addition applied within ±5% of the set point.
When the installation is exposed to mechanical vibration, such as near pumps or compressors — option QA dampens dial vibration up to 65°C ambient.
An optional dampening liquid available specifically on the electrical contact version of the CA Model.
Sheet glass on the standard version, plexi glass on the silicon-oil-filled version, and a polycarbonate dome on the electrical contact version.
Yes — the pointer includes micrometer zero adjustment as standard.
Yes, option PS provides an AISI 316 SS case and bezel, available for NS 100mm to 150mm dials.
Yes, option PW provides a five-point calibration certificate for the specified measuring range.
Yes, option GH provides material test certificates for wetted parts with chemical composition testing.
Yes, option PY provides glycerin dampening fill for ambient temperatures up to 65°C.
Option SJ adds a maximum reading pointer with plexi glass, available on the dry version for NS 100mm to 150mm dials, useful for recording peak temperature exposure.
Chemical, food, pharmaceutical, pulp, paper, refinery, cement, and other process industries handling corrosive media where remote temperature indication is beneficial.
CA . [Nominal Size] . [Mounting Type] . [Process Connection] . [Connection Type] . [Stem Diameter] . [Stem Length] . [Range] . [Type A1/A2] . [Capillary Length] . [Capillary Material] . [Armour] . [Electrical Contact Code] . [Optional Extras].
Yes, using process connection type KJ; NPT and BSPT threads are not recommended for revolving/swivel connections.
Yes. Zebco Engineering LLP is an authorized Baumer dealer supplying pan India and internationally, with export documentation support. Contact +91 98982 26321 or sales@zebcoeng.com.
Lead time depends on dial size, capillary length and electrical contact options selected; share your specification with our team for a project-specific lead time.
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