www.sensirion.com

version 1.0 – December 2021

3/22

1 Sensor Performance

Table 1 lists specifications characterizing the gas sensing performance. The SGP41 chip provides two digital raw signals which

raw signals are proportional to the logarithm of the resistance of the sensing material. For the specifications given below, ethanol

gas for typical oxidizing gas based indoor air events.

Parameter

Conditions

Units

Min.

Typ.

Max.

Output signal

VOC Index, processed value from SRAW_VOC

1

–

500

VOC Index points

1

–

500

SRAW_VOC, digital raw value from VOC pixel

0

–

65’535

0

–

65’535

ticks

Measurement

range

Ethanol in clean air

0

–

1’000’000 ppb

0

–

10’000

ppb

Specified range

Ethanol in clean air

500

–

10’000

ppb

50

–

650

ppb

Device-to-device

VOC Index

–

<±15

<±15

–

VOC Index points

or

% m.v.

(the larger)

–

<±50

<±50

–

or

% m.v.

(the larger)

Repeatability4

VOC Index

–

<±5

<±5

–

VOC Index points

or

% m.v.

(the larger)

–

<±5

<±5

–

or

% m.v.

(the larger)

else clean air

–

–

<50

or

<10

ppb

or

% of concentration setpoint

(the larger)

–

–

<20

or

<10

Response time

to 10’000 ppb of ethanol at sampling interval of 1 s

–

<10

–

s

SRAW_NOX, changing concentration from 150 to

–

<250

–

s

1

99 % of the sensors will be within the minimum–maximum tolerance. Typical tolerance refers to the mean of the distribution for ≥100 sensors.

2

Humidity compensated when actual humidity value is provided as input to the sensor (see section 3.2 Raw Signal Measurement).

3

Signal in ticks is proportional to the logarithm of the resistance of the sensing layer.

4

Evaluated using the calibration and test sequence according to the application note SGP41 – Testing Guide.

5

Limit of detection is defined as the minimum change of concentration required to obtain a raw signal change 3 times higher than the noise at the given concentration setpoint.

6

Parameter tested over simulated lifetime of 10 years in an indoor environment. Test conditions: continuous operation in 250 ppm of Decamethylcyclopentasiloxane (D5) for

200 h.

7

A concentration of 500 ppb of ethanol corresponds to the equivalent of a typical VOC background present in an application environment, e.g., a typical OEM device.