Text Box: OFS1 
 Oxygen & Flow Rate Sensor 
 Oxygen (±1.5%)
Flow rate ±0-20 L/min (±0.1 L/min)
4ms response
USART, LCD & Analog outputs 
Operating temperature range –45 to +70ºC




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 Volumetric Flow rate sensor. OFS1 is powered by 8V to 35V / 14mA unregulated DC Power Supply. OFS1 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. 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   Oxygen Measurement applications. Flow direction Alarm output can detect wrong direction of Flow.                            .



Text Box: info@dgflo.com


 4.6 x 0.8x 0.5” / 25g

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 0—20 L/min

Analog O2 output

0 to 5V DC Linearly proportional to 0—100% 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 +45°C; ±2% @ -45°C to –5°C,  45°C to +70°C

Flow Resolution

±0.1 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 70°C

Survival Temperature

-85 to +85°C

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 1/8” male barbs

Response Time

 4 ms

USART Frame content

O2 [%], Flow Rate[L/min], Temperature[°C], Hours of operation

10Hz Square wave output

J1.6 5V P-P

Flow Direction Indicator

J1.3—Open 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