General Description

EtOH sensor is a miniature metal oxide semiconductor gas sensor based on MEMS micro hotplate technology for detection a wide rang of organic solvent vapor in air.

Sensor production combined with silicon substrate MEMS technology, thin film technology, thick film technology and ceramic packaging technology.

The gas sensitive layer is deposited at the top of the hotplate and interdigitated electrodes, resulting in a conductivity dependent on the concentration of harmful gases.

Features:

High sensitivity and large dynamic range to organic

solvent vapor ( 1~1000ppm )

Quick response (~10Sec.)

Very low power consumption ( 40~42mW )

Small size  ( 3.8mm × 3.8mm × 1.5mm )

Long operating life ( ~10 Years )

Reflow soldering

Applications:

Organic solvent vapor leakage alarm

Alcohol detection

IoT, wearable devices, smart home

Performance parameter

Package outline

Pin connections

Pin    Function

1       Heater Electrode 1

2       NA

3       Sensor Electrode 1

4       NA

5       Heater Electrode 2

6       NA

7       Sensor Electrode 2

8       NA

Heater Circuit

Sensor Circuit

Remarks

1,  R0 is tested under standard environmental conditions, i.e., in a clean air with a temperature of 25 ± 3 C and a humidity of 50 ± 10%.

2,  S5  is defined as R0/Rg , Rg  is the sensor resistance in the air of  5ppm ethanol concentration, 25 ± 3 C, 50 ± 10%.

3, The response time and recovery time is defined as the time interval from the contact the specified gas concentration to the 70% of the stable resistance variation.

4,  RH is measured in the condition of heating power 40~42mW,

and will change with heating power changes. This feature can be used to do temperature compensation.

5,  VS   is  the  voltage  applied  to  the  sensor  electrodes,  and should be kept ≤ 5.5V in working condition. Too high voltage will  shorten  the  service  life  of  the  gas  sensor  and  even damage the gas sensor.

6,  Ps is the power applied to the sensor electrodes, and should not be greater than 1mW .

Operating Environment

Typical measurement circuit

Remarks

VH:  5.0VDC ± 2%

Vc:   5.0VDC ± 2%

R1: 120Q. The heating power can be adjusted by R1. In order to   obtain   ideal   gas   sensing characteristics,     the     heating power of the gas sensor should be within 40~60mW .

RL : 10~50 kQ     RL  ≥5 kQ to

avoid the gas sensor damage.

The  sensor  has  no  polarity. Pin 1 and 5 are interchangeable, and   Pin   3   and   7   are   also interchangeable.

In   order   to   maximize   the performance advantages of the gas   sensor,   the   temperature compensation   of   the   heating circuit    can    be    carried    out. Please   contact   us   for   more detailed information.

Recommended pad size

(Unit: mm)

Sensitivity characteristics

The figure below shows a typical gas sensor sensitivity characteristic curve. The Y-axis shows the ratio Rg/R50 . The X-axis shows the test gas concentration. where Rg  is the resistance value of the  gas  sensor  in various  concentrations  of gas, and R50 is the resistance value of the sensor in 50ppm alcohol concentration.

Attentions

Please read the following terms carefully to avoid product data errors and prevent product damage.

1.  The gas sensor must be reflow soldering in neutral atmosphere. The welding furnace  should  have sufficient flow of clean air to maintain the air clean. The  maximum  temperature  is  260C.  Manual soldering  conditions  are  recommended  for  a maximum temperature of 350 C for 5 seconds. it is recommended that it should be aged for more than 4 hours to eliminate the influence of welding process on the gas sensor.

2.  The vacuum adsorption hole should be in the non porous  area of the sensor upper cover during SMT process. Select appropriate nozzle size and SMT parameters to prevent the sensor damage.

3.  Products   should   not   be   exposed   to   high concentrations of organic solvent vapor, silicone vapor,  in  order  to  prevent  sensitive  material poisoning.

4.  The product should be placed in the filter protected space to prevent water and dust. If necessary, the installation direction can be used to prevent dust deposition.

5.  The    sensor    resistance    will    experience    a continuous  increase  after  power  on.  The  time span of this process depends on the sensor heat history and storage environment. The longer time is   needed   when   off   time   is   long.   It   is recommended to preheat at least 60 min. to get a reliable results. Preheat time can be reduced by appropriately increasing heating power (<60mW).

6.  It   is   recommended   to   use   ESD   protection equipment when handling the products.

7.  It is recommended to use our filter cover to realize waterproof, oil drainage and dust prevention.

Temperature and humidity dependence

The figure below show a typical characteristic curve    of    gas    sensor    is    influenced    by temperature  and  humidity.  The  Y-axis  shows the ratio Ra/R0 . The X-axis shows the working temperature. Where Ra  is the resistance value of the gas sensor  under various temperatures and humidity in the clean air.

Package

Tape and reel. (1000 pcs). Other packaging methods can also be provided according to customer requirements.

Environmental Protection

This product conforms to the current RoHS directive and can pass REACH certification. The product does not contain environmentally restricted chemicals.