GREENFLASH SOLID STATE O2 SENSOR

Welcome to the short manual of the GREENFLASH SOLID STATE O2 SENSOR.

USPs

Long Lifetime, typically 5y +
Integrated user replaceable battery (no corrosion on the contacts)
Analog mode (10mV @ 0.21 bar pO2)
Digital mode
Automatic selection of the mode
Patented

Safety Considerations

Before using the GREENFLASH SOLID STATE O2 SENSOR you must read and understand the information provided in this manual in its entirety. In this manual the following precautionary symbols are used to indicate the following important precautionary statements. Those statements provide information about potential hazards and proper procedures. Three different safety signs are used to rank their importance: red stands for vital information, which shall not be ignored under any circumstances; yellow advises for caution; blue indicates technical or other recommendations for safe and reliable operation of the device.

WARNING statements describe potentially hazardous situations, if not avoided, could result in death,or serious injury. Avoid these situations under any circumstances.

Before using the GREENFLASH SOLID STATE O2 SENSOR, read the manual in its entirety
Before using the GREENFLASH SOLID STATE O2 SENSOR, read the manual in its entirety and get familiar with all the functions of the device.
This sensor is designed for industrial measurement purposes only.
Do not use this sensor in life supporting systems, unless the system is certified for use with this sensor.
Do not use this sensor for medical applications.

CAUTION indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.

Do not operate the sensor in bright light as the internal amplifiers may get overloaded and as result the sensor measurements may be incorrect.
Do not operate the sensor in an environment illuminated with fluorescence light. Fluorescence light can disturb the sensor readings.

WARNING statements describe potentially hazardous situations, if not avoided, could result in death,or serious injury. Avoid these situations under any circumstances.

Do not expose the sensor to bright sunlight. Sunlight may bleach and damage the sensor spot.

Measurement Principle

The GREENFLASH SOLID STATE O2 SENSOR features an O2 sensitive sensor spot, which incorporates a special color dye. When this color dye is excited with green light, it starts fluorescing and emits red light. O2 quenches the fluorescence, thus the higher the partial pressure of O2 the lower is the amplitude and lifetime of the red fluorescence signal.

The GREENFLASH SOLID STATE O2 SENSOR excites the sensors spot with a green light modulated with a sinusoidal signal. The fluorescence signal is acquired with a high speed ADC: measured. Then the GREENFLASH SOLID STATE O2 SENSOR performs a Fast Fourier Transformation to calculate amplitude and lifetime of the fluorescence, a temperature compensation, and finally calculates the pO2 based on calibration values that were obtained during the production process of the sensor.

The GREENFLASH SOLID STATE O2 SENSOR switches automatically between 3 operational modes:

Sleep Mode: If the sensor is not installed, it is in Sleep Mode to conserve battery power. In this mode it measures once each 20s if it is installed in a measurement device.
Standby Mode: In this mode, it performs a pilot measurement each 15s. If then the measured pO2 is greater than 0.3 bar, the sensor will enter measurement mode.
Measurement Mode: In this mode, it will perform a measurement each 2 seconds and will, depending on the electrical interface, output analog or digital data. Once the pO2 falls below 0.3 for at least one hour, the sensor will exit measurement mode and return to Standby Mode.

Electrical Interface

The GREENFLASH SOLID STATE O2 SENSOR features a patent pending smart interface, which allows to use the sensor in analog as well as digital instrumentation:

GREENFLASH SOLID STATE O2 SENSOR with SMB connector

GREENFLASH SOLID STATE O2 SENSOR with MOLEX connector

GREENFLASH SOLID STATE O2 SENSOR with MOLEX connector and external supply (3 - 3.3V, 15mA peak)

Analog Interface

If the GREENFLASH SOLID STATE O2 SENSOR is installed in a measurement device with an input impedance between 10kOhm and 150kOhm, the GREENFLASH SOLID STATE O2 SENSOR will output an analog signal with a slope of approximately 10mV @ 0.21bar pO2.

Digital Interface

If the output of the GREENFLASH SOLID STATE O2 SENSOR is loaded with a resistor < 3kOhm, the GREENFLASH SOLID STATE O2 SENSOR will output a digitally current coded serial signal.

single wire USART
115200 BAUD
Logic Low ~ 0..5µA
Logic High ~ 50..150µA

The output string includes the following values:

pO2 [bar]
Raw value 1
Raw value 2
temperature [°C]
battery voltage [mV]
serial number of the sensor

Please contact OXYGEN SCIENTIFIC for further information concerning the digital current coded serial interface of the GREENFLASH SOLID STATE O2 SENSOR.

Single Wire Serial Interface

If the output of the GREENFLASH SOLID STATE O2 SENSOR is connected with a pull up resistor of 5.6k to a 3-3.3V level, it will enter single wire bi-directional USART mode.

single wire USART
115200 BAUD

The GGREENFLASH SOLID STATE O2 SENSOR will transmit each 2s "X\n" as alive signal.

Available commands:

"Mn\n" returns the pO2 [bar]

"Tt\n" returns the temperature [°C]

Please contact OXYGEN SCIENTIFIC for further information concerning the serial single wire bi-.directional interface of the GREENFLASH SOLID STATE O2 SENSOR.

Specifications

Measurement range pO2: 0.1..2bar
Measurement range O2 fraction: 10..100% O2
Response time t63~2s
Thread: M16x1
Operating temperature: 0..40°C
Storage Temperature: -10..50°C
Accuracy: compliant to ISO80601-2-55:2018
Supply: Li Ion battery, CR2477
Battery capacity: >900mAh

Troubleshooting

Fluctuating/unstable signals

The GREENFLASH SOLID STATE O2 SENSOR produces fluctuating signals:

Protect the sensor from ambient light

No output

The GREENFLASH SOLID STATE O2 SENSOR blinks green once each 15s, but does neither output digital or analog data:

Expose the sensor to a pO2 greater than 0.3 bar
Check the electric connection
Check if the input impedance of the measurement system the sensor is connected to, matches the specification of the GREENFLASH SOLID STATE O2 SENSOR

No blinking

The GREENFLASH SOLID STATE O2 SENSOR is installed in a measurement device but does not blink green once each 15s:

Check the electric connection
Check if the input impedance of the measurement system the sensor is connected to matches the specification of the interface
Replace the battery, if the voltage of the battery is below 2.3V

Blinking each 15s

The GREENFLASH SOLID STATE O2 SENSOR is not installed in a measurement device but still blinks each 15s:

let the sensor dry. Most likely humidity is in the connector and the sensor does not see high impedance.

Blinks each 2s

The GREENFLASH SOLID STATE O2 SENSOR is not installed in a measurement device and blinks each 2s:

wait half an hour and let the sensor dry

Blinks, but no analog output

The GREENFLASH SOLID STATE O2 SENSOR is installed in an analog measurement device, blinks each 2s, but does not output a stable mV signal:

protect the sensor from ambient light
the sensor may be locked to digital mode. The sensor needs to be reset to be able to use it in analog mode. This can be done by removing the battery for 1 min or by sending a reset command via single wire serial interface.

Blinks, but no digital output

The GREENFLASH SOLID STATE O2 SENSOR is installed in a digital device, blinks each 2s, but the digital device does not read data:

check the connector for humidity and let it dry
if the sensor is in analog mode, wait for half an hour till the sensor exits analog mode (during this time the sensor has to be exposed to a pO2 < 0.3 bar and should be protected from light)