Oxygen concentrator spec sheets look simple, but the important details are often hidden in how the numbers are stated. This guide explains the fields that actually affect buying and ownership.
Flow rate
Flow is listed in litres per minute, usually as 0.5-5 LPM, 1-5 LPM, or 1-10 LPM. The device must meet the patient’s prescribed continuous flow at rated purity.
Do not buy based on maximum flow alone. A 10 LPM device is not automatically better than a 5 LPM device for a 2 LPM prescription.
Purity
The normal honest specification is around 90-96% or 93% +/- 3%. That range reflects the practical PSA oxygen concentrator envelope.
Be cautious when a listing claims unusually high purity without stating flow rate, test method, and tolerance. Purity should be assessed at the flow the patient will actually use.
Oxygen purity indicator
OPI, OCI, or oxygen purity analyzer support warns when delivered oxygen concentration falls below a threshold. It is especially valuable for long-term users because sieve-bed degradation can be gradual.
If a device lacks OPI, plan periodic oxygen-analyzer checks.
Sound level
Sound should be stated as dB(A), ideally at 1 meter and rated flow. Under 45 dB is generally better for bedroom use. 45-50 dB can work with placement. Above 50 dB is usually intrusive at night.
Power draw
Power draw affects electricity cost and backup sizing. Common 5 LPM devices range from about 285 W to 550 W. Common 10 LPM devices range from about 530 W to 850 W.
For long-duration oxygen use, this is not a minor spec.
Weight and dimensions
Weight matters if the caregiver moves the device. A 13-14 kg 5 LPM unit is much easier to reposition than a 25 kg unit. Dimensions matter in small bedrooms because concentrators need ventilation clearance.
Outlet pressure
Outlet pressure affects tubing runs and some accessory setups. Higher outlet pressure can help with longer tubing, but it does not replace medical flow verification. If the setup uses long cannula tubing, verify flow at the patient end.
Altitude rating
Altitude affects oxygen delivery because inlet oxygen partial pressure falls. If the patient lives in or travels to hill stations, check operating altitude and discuss flow adjustment with the treating clinician.
Certifications
Common claims include CE, FDA, CDSCO, ISO 13485, and ISO 9001. These claims are not equivalent.
- CE should be verifiable through the certificate and Notified Body where applicable.
- FDA claims should ideally identify the 510(k) or registration context.
- CDSCO approval matters for Indian regulatory status.
- ISO 13485 is a quality-management certification, not a performance test.
Warranty
Read warranty duration and exclusions. Look for compressor coverage, sieve-bed coverage, voltage exclusions, service-center access, and whether warranty follows the serial number or invoice.
Red flags
- Purity claims above the normal PSA envelope with no test method.
- No OPI on a long-term oxygen device without a testing plan.
- No local service path.
- Warranty with broad voltage or dust exclusions but no installation guidance.
- Listing images that do not match the exact model name.
- Extremely low prices for high-spec claims.
Bottom line
A good concentrator spec sheet tells you flow, purity, OPI, noise, power, weight, outlet pressure, voltage range, warranty, and service route clearly. If those fields are vague, treat that as part of the product evaluation.
This guide is equipment education. Always match concentrator choice to a physician’s oxygen prescription.