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Version 3.3 – November 2024

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3.3.3 Set relative humidity

Accurate concentration measurement requires compensation of humidity because the measurement principle

of the concentration measurement is dependent on the humidity of the gas. The new low-cross-sensitivity

mode reduces this sensitivity by smart internal compensation to a minimum. If possible, it is still recommended

to compensate for relative humidity with the SHT4x and to update the compensation input whenever the

relative humidity changes significantly (see Engineering Guide).

Command

Command

code (Hex)

Argument

Description

Set relative

humidity

0x3624

Relative Humidity: 16bit

unsigned integer

For relative humidity

scaling, see section 3.5.3.

When no value is written to the sensor after a

soft reset, wake-up or power-up, a relative

humidity of 0% is assumed.

The value written to the sensor is used until a

new value is written to the sensor.

This command sequence needs to be closed off with a valid CRC byte for the 16-bit argument if the CRC is not

disabled.

When the CRC byte does not match the argument, the sensor will respond with a NACK. The sensor will omit

the command and will use the previous value, or when no value was written, assume a relative humidity of 0%.

3.3.4 Set temperature

Accurate concentration measurement requires a compensation of temperature. It is recommended to use the

temperature value of the SHT4x, because it is more accurate. When no value has been written since start-up,

the sensor uses the internal temperature signal. The temperature compensation input must be updated

whenever the temperature changes significantly (see Design Guide).

Command

Command

code (hex)

Argument

Description

Set temperature

0x361E

Temperature: 16bit

signed integer

(two's complement

number)

For temperature scaling,

see section 3.5.2.

When no value is written to the sensor after a

soft reset, wake-up or power-up, the internal

temperature signal is used.

The value written to the sensor is used until a

new value is written to the sensor.

This command sequence needs to be closed off with a valid CRC byte for the 16-bit argument if the CRC is not

disabled.

When the CRC byte does not match the argument, the sensor will respond with a NACK. The sensor will omit

the command and will use the previous value, or when no value was written, the internal temperature signal.