April 13, 2021
Maxell Holdings, Ltd.

Maxell develops lead-free galvanic cell-type oxygen sensors suitable for medical use,
enabling measurement at high oxygen concentration
Compliant with RoHS directive *1 while achieving 20% longer*2 life

Lead-free galvanic cell-type oxygen sensor KE-25F3LFM

Maxell, Ltd. (President and Representative Director: Keiji Nakamura, hereinafter “Maxell”)
announced that it started sample shipment of lead-free galvanic cell-type oxygen sensors(hereinafter “lead-free oxygen sensor”) using weak acid electrolyte solution which are capableof measuring over a range of 0-100% oxygen. These sensors are compliant with RoHS
directive*1 and are not influenced by CO2. Therefore, they are suitable in medical devices suchas artificial ventilator, anesthesia apparatus and infant incubator which require high oxygen
concentration measurement, as well as in fields such as combustion gas monitoring,biotechnology equipment, food storage, and education.
Main Features of Maxell’s Lead-Free Galvanic Cell-type Oxygen Sensor
1. Expanded measuring range of 0-100% O2
2. 20% longer*2 life expectancy than conventional products (6 years)
3. Compliant with RoHS directive*1
4. Virtually no influence from CO2, H2S, SO2
Due to the limited measuring range of 0-30% O2, conventional lead-free oxygen sensors were
not able to be used in medical applications and fields where measurement of high oxygen
concentration is required. Maxell succeeded in stable measurement of high oxygen
concentration, which causes a load increase on oxygen sensors, by changing components of
newly developed lead-free oxygen sensor. This made it possible to measure over a range of 0100% O2 and to extend the life expectancy 20% longer*2 than conventional products.
Additionally, newly developed lead-free oxygen sensor is not influenced by CO2 using
originally developed weak acid electrolyte solution, as with all other Maxell’s conventional
products. In medical fields, the oxygen sensors which are unaffected by CO2 are required1

because the gas exhaled from human contains approximately 4% CO2. Newly developed leadfree oxygen sensor KE-25F3LFM is compliant with RoHS directive*1as with Maxell’s otherlead-free oxygen sensors, and can be used in medical fields.
Maxell has been contributing to the reduction of the environmental load throughcommercializing lead-free oxygen sensors compliant with RoHS directive*1 since 2019. Due toa high degree of technical difficulty to achieve lead-free oxygen sensors, conventional oxygensensors which contain lead are exempted from RoHS directive*1. However, the exemption will
eventually be expired for oxygen sensors used in applications, such as medical devices andmonitoring and control instruments in the future.
Maxell will contribute to solutions for societal problems, such as SDGs, through thedevelopment of environmentally friendly products by enhanced technologies in response todomestic and overseas market demands.
*1 RoHS directive: Refer to the description shown in 2011/65/EU and EU2015/863.
*2 20% longer: In comparison with KE-25F3LF

Product details
Galvanic Cell-type Oxygen Sensor
https://biz.maxell.com/en/tokki/oxygen_sensors.html
About SDGs
Maxell will contribute to reducing a risk of soil or ocean pollution or
harmful impacts on the human body, through the development of leadfree galvanic cell-type oxygen sensors.
Contacts
Marketing & Sales Div., Maxell Ltd.
E-mail: contact-maxellbattery@maxell.co.jp
Inquiries: https://www.maxell.co.jp/inquiry/maxell/en/form.jsp?f=biz&q=tokki_en_biz

2Appendix
Influence of CO2 on lead-free galvanic cell-type oxygen sensor KE-25F3LFM
Newly developed lead-free oxygen sensor KE-25F3LFM is not influenced by CO2 because it
uses originally developed weak acid electrolyte solution. The graph below shows theinfluence of CO2 on KE-25F3LFM. When normal air (21% O2), N2 (0% O2), 100% CO2 (0%O2), N2 (0% O2), normal air (21% O2) are flowed into the oxygen sensor in order, the output
voltage is not affected from N2, 100% CO2, N2, and the initial and final sensor output voltage
in normal air are stable and equivalent. Therefore, it is concluded that KE-25F3LFM is
unaffected by 100% CO2 and the accurate oxygen concentration can be measured even in thecoexistence of CO2.

Influence of CO2 on lead-free galvanic cell-type oxygen sensor KE-25F3LFM

Specifications
Model No.

KE-25F3LFM

Measurement range

0 ~ 100% O2Linearity accuracy±1 % Full Sale

Operating pressure range

811 ~ 1216 hPa

Operating temperature range

5 ~ 40°C

Response time (90%)

approx. 15sec.

Life expectancy*1

approx. 108 ×104 %h
approx. 6 years at 20°C

Appearance

Cylindrical, Threaded top*1 Life expectancy: when the product is used at 20˚C with a humidity of 60%RH and atmospheric pressure of1013hPa, represented as a value of (Oxygen Concentration %) × (Time h)* Specifications of the sample products are subject to change without notice.

3Dimensions###