At-line Digital CO2 meter for beer and carbonated beverages (CO2 GEHALTEMETER) Type GMD
The digital CO₂ meter type GMD enables enables the determination of CO₂ content in beer, carbonated beverages and sparkling wines in cylindroconical tanks, conditioning tanks or KEG casks, expressed in volumes and g/L.
Measurement Principle:
The instrument uses Henry’s law. The CO₂ content is determined by measuring the temperature and the partial pressure of CO₂ in equilibrium after mechanical shaking of the beverage. A piston allows carbon dioxide to be released very quickly, eliminating the need to shake the device. This allows measurements to be taken more quickly and minimises temperature variations.
Working Procedure:
The inlet valve of the device is connected using a silicone hose to the sampling valve on the pipeline or tank. The measuring chamber is filled with sample. The beverage flow through the measuring chamber can be finely regulated using a screw discharge valve to prevent foam formation during filling. Once the measuring chamber is filled, the outlet valve is closed first, followed by the inlet valve. Then the pressure in the measuring chamber is zeroed by brief opening and closing of the outlet valve. Dissolved CO₂ is released by repeatedly pulling and pressing a piston in the upper part of the measuring chamber, increasing the pressure inside the chamber. Pressing the Enter button initiates the measurement. The device automatically measures pressure and temperature, calculates CO₂ content and displays results in g/L and volumes.
Technical data:
| Parameter | Range / Value | Accuracy |
| CO₂ measurement | 2 to 9.99 g/L (1 to 5.15 vol) | 0.1 g/L or 0.05 vol |
| Temperature | −3 to +30 °C | 0.1 °C |
| Pressure | 0–600 kPa (0–6 bar) | 0.5 % |
| Display | Digital, 4×20 characters | — |
| Data memory | 400 measurement samples | — |
| Dimensions (H×W×D) | 270×190×300 mm | — |
| Weight | 2.8 kg | — |
Scope of Delivery:
CO₂ meter GMD, inlet and outlet silicone hoses, rechargeable adapter, operation manual.
Accessories (optional):
Sampling head for KEG casks (not included in standard delivery, available on request).
Advantages & Benefits:
- High accuracy & calibration capability — suitable for ISO 9001/9002 laboratories.
- Fast & reproducible CO₂ release using pressure pulse generated by piston.
- In addition to CO₂ measurement, the device allows for independent measurement of temperature and pressure.
- 25+ years of manufacturing experience, thousands of units in operation worldwide.
- Repairable, spare parts available.
- Excellent price-to-performance ratio.
Downloads
Product sheets, catalogues and technical documentation.
Frequently asked questions
Differences between GMAS, GMA and GMD models?
- GMAS & GMA are analog with nomogram-based CO₂ reading.
- GMD measures pressure & temperature automatically and displays CO₂ in g/L and volumes.
- GMD & GMA release CO₂ via piston pressure pulse (fast & reproducible).
- GMAS requires manual shaking until steady pressure (slower, less reproducible, cheapest).
Here is an overview table of the differences and characteristics of the individual types:
| Function / Feature | GMAS | GMA | GMD |
| Measurement Type | Analog (manometer) | Analog (manometer) | Digital (display) |
| CO₂ Release Method | Manual shaking | Pressure impulse by piston | Pressure impulse by piston |
| Result Determination | Nomogram | Nomogram | Automatic calculation |
| Speed and Accuracy | Lower (operator dependent) | High (reproducible) | Highest (automated) |
| Price Level | Most affordable | Mid-range (excellent price/performance ratio) | Premium |
What are the advantages and disadvantages of a 3.5″ color touchscreen compared to a 4×20 character monochrome LCD?
- Touchscreen = user-friendly.
- Conversely, the device with an LCD display is more cost-effective and offers significantly longer battery life, reducing the need for frequent recharging.
Note: At the customer’s request, the GMD can be equipped with a colour touch display for an additional charge.