Text Box: OFS2 
 Oxygen & Flow Rate Sensor 
 Oxygen (1.5%)
Flow rate 0-500 L/min (1 L/min)
4ms response
USART, LCD & Analog outputs 
Operating temperature range 45 to +70C




1. Oxygen Concentrator sourced O2 mixture. (J1.4 open)

2. Medical/Hospital Ventilator Oxygen/Air mixer sourced O2 mixture. (J1.4 Set to GND)

In circuit configurable to measure the Oxygen content in one of these gasses.


Ultra fast and miniature - Oxygen and High Volumetric Flow rate sensor. OFS2 is powered by 8-35V / 14mA unregulated DC Power Supply. OFS2 provides: 0-5V DC proportional outputs; UART bit stream comprising: O2 concentration, Volumetric Flow Rate, temperature and operational hours. 4ms response is ideally suited for crisp flow rate measurement & closed loop control applications. Time constant, bi-directionally stable response enables detection of Start of Breath and calculation of spirometry parameters. Thermal characteristics allow automotive, high altitude and other high Flow rate Oxygen Measurement applications. Flow direction Alarm output can serve to detect wrong direction of flow.




Text Box: info@dgflo.com


4.6 x 0.8 x 0.5 / 45g

Oxygen types

Controlled by J1.4 O2 concentrator or air mixtures with pure O2


UART, LCD, Analog

Analog Flow output

0 to 5V DC Linearly proportional to 0500 L/min

Analog O2 output

0 to 5V DC Linearly proportional to 0100% O2

Power Supply

Unregulated 8V to 32V DC / 14 mA

Display Switch

Performs Field Calibrations & Toggles between O2 & Flow on DigiDISP

O2 Accuracy

1.5% @ 5 to +45C; 2% @ -45C to 5C, 45C to +70C

Flow Resolution

1 L/min

O2 Range

20.8% - 95.7%, 20.8% - 100%

Max pressure

30 psig

Thermal change response

1 oC/min

Thermal Gradientmax

50 K/m

Operating Temperature

-45 to 70C

Survival Temperature

-85 to +85C

RS232 transmit Rate

200 bytes/sec @ 19200 bits/sec

Calibration Retention

More than 10 years


Factory. Optional field calibration is provided.

Flow I/O

Bi-directional via 1/2 male barbs

Response Time

4 ms

UART Frame content

O2 [%], Flow Rate[LPM], Temperature[C], Hours of operation

10Hz Square wave output

J1.6 5V P-P

Flow Direction Indicator

J1.3Open Drain

Long term display & save

Via DigiTEST


to other units of Flow

How to convert Volumetric Flow to other units of Flow Rate, such as gal/min, SLPM