Sensori Sensirion SHT4x con riscaldatore incorporato

**zoomx** · 22/03/2024, 21:35

A quanto pare i sensori della serie SHT4x incorporano un riscaldatore, credo per eliminare la condensa interna.

4.9 Heater Operation
The sensor incorporates an integrated on-package heater which can be switched on by the set of commands
given in Table 8. Three heating powers and two heating durations are selectable and given in Table 9. After
reception of a heater-on command, the sensor executes the following procedure:
1. The heater is enabled, and the timer starts its count-down.
2. On timer expiration a temperature and humidity measurement with the highest repeatability is
started, the heater remains enabled.
3. After the measurement is finished the heater is turned off.
4. Temperature and humidity values are now available for readout.
The maximum on-time of the heater commands is one second in order to prevent overheating of the sensor
by unintended usage of the heater. Thus, there is no dedicated command to turn off the heater. For extended
heating periods it is required to send periodic heater-on commands, keeping in mind that the heater is
designed for a maximal duty cycle of less than 10%. To obtain a fast increase in temperature the idle time
between consecutive heating pulses shall be kept minimal.
Parameter Selectable Values
Heater Power (for VDD=5V) 0 (=off), 20, 110, 200 mW
Heater-on Duration (tHeat) 0.1, 1 s
Maximal duty cycle 10%
Table 9. SHT4xI-Digital heater specifications.

**Matteo97** · 25/03/2024, 10:17

Originariamente Scritto da zoomx

A quanto pare i sensori della serie SHT4x incorporano un riscaldatore, credo per eliminare la condensa interna.

4.9 Heater Operation
The sensor incorporates an integrated on-package heater which can be switched on by the set of commands
given in Table 8. Three heating powers and two heating durations are selectable and given in Table 9. After
reception of a heater-on command, the sensor executes the following procedure:
1. The heater is enabled, and the timer starts its count-down.
2. On timer expiration a temperature and humidity measurement with the highest repeatability is
started, the heater remains enabled.
3. After the measurement is finished the heater is turned off.
4. Temperature and humidity values are now available for readout.
The maximum on-time of the heater commands is one second in order to prevent overheating of the sensor
by unintended usage of the heater. Thus, there is no dedicated command to turn off the heater. For extended
heating periods it is required to send periodic heater-on commands, keeping in mind that the heater is
designed for a maximal duty cycle of less than 10%. To obtain a fast increase in temperature the idle time
between consecutive heating pulses shall be kept minimal.
Parameter Selectable Values
Heater Power (for VDD=5V) 0 (=off), 20, 110, 200 mW
Heater-on Duration (tHeat) 0.1, 1 s
Maximal duty cycle 10%
Table 9. SHT4xI-Digital heater specifications.

Ciao, quindi non induce alcuna influenza ai sensori?

**zoomx** · 26/03/2024, 11:25

No, visto che è prevista. Il riscaldamento dura un tempo prefissato, un secondo, che non è possibile modificare proprio per evitare problemi.
Bisogna vedere però se tale nuova caratteristica viene utilizzata.

**Matteo97** · 26/03/2024, 23:49

Originariamente Scritto da zoomx

No, visto che è prevista. Il riscaldamento dura un tempo prefissato, un secondo, che non è possibile modificare proprio per evitare problemi.
Bisogna vedere però se tale nuova caratteristica viene utilizzata.

Interessante, per il periodo di campionamento più lungo o più dispendioso di energia?