www.sensirion.com / D1

Version 1

– October 2020

4/16

2 Humidity and Temperature Sensor Specifications

2.1 Relative Humidity

Parameter

Conditions

Value

Units

SHT40 RH accuracy1

typ.

1.8

%RH

max.

see Figure 2

-

SHT41 RH accuracy1

typ.

1.8

%RH

max.

See Figure 3

-

SHT45 RH accuracy1

typ.

1.5

%RH

max.

tbd

-

Repeatability2

high

0.08

%RH

medium

0.15

%RH

low

0.25

%RH

Resolution3

-

0.01

%RH

Hysteresis

-

1

%RH

Specified range4

extended5

0 to 100

%RH

Response time6

t63%

6

s

Long-term drift7

typ.

<0.25

%RH/y

Table 1: General relative humidity sensor specifications.

Figure 2: SHT40 typical and maximal relative

humidity accuracy at 25 °C.

Figure 3: SHT41 typical and maximal relative

humidity accuracy at 25 °C.

1 For definition of typ. and max. accuracy, please refer to the document “Sensirion Humidity Sensor Specification Statement”.

2 The stated repeatability is 3 times the standard deviation (3σ) of multiple consecutive measurement values at constant conditions and is a measure for the noise

on the physical sensor output. Different repeatability commands are listed in Table 7.

3 Resolution of A/D converter.

4 Specified range refers to the range for which the humidity or temperature sensor specification is guaranteed.

5 For details about recommended humidity and temperature operating range, please refer to section 2.3.

6 Time for achieving 63% of a humidity step function, measured at 25°C and 1 m/s airflow. Humidity response time in the application depends on the design-in of the

sensor.

7 Typical value for operation in normal RH/T operating range. Max. value is < 0.5 %RH/y. Value may be higher in environments with vaporized solvents, out-gassing

tapes, adhesives, packaging materials, etc. For more details please refer to Handling Instructions.

±0

±2

±4

±6

±8

0

10 20 30 40 50 60 70 80 90 100

Relative Humidity (%RH)

SHT40 typ

SHT40 max

DRH (%RH)

±0

±2

±4

±6

±8

0

10 20 30 40 50 60 70 80 90 100

Relative Humidity (%RH)

SHT41 typ

SHT41 max

DRH (%RH)