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Version 0.8 – January 2017

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5.3.1 Start Continuous Measurement

The sensor measures both the differential pressure and temperature. Both measurement results can be read out through one

Continuous measurements can be started up in different configurations by a set of commands.

Command code (Hex) Temperature compensation

Averaging

0x3603

Mass flow

Average till read

0x3608

Mass flow

None - Update rate 1ms

0x3615

Differential pressure

Average till read

0x361E

Differential pressure

None - Update rate 1ms

After one of the commands has been sent, the chip continuously measures and updates the measurement results. New

measurement command has been sent.

After the start measurement command is sent:

-

the first measurement result is available after 8ms;.

-

small accuracy deviations (%mv) can occur during the next 12ms.

bit).

Preceding

command

Consecutive read

Description

continuous

measurement

Byte1: Differential Pressure 8msb

Byte2: Differential Pressure 8lsb

Byte3: CRC

Byte4: Temperature 8msb

Byte5: Temperature 8lsb

Byte6: CRC

Byte7: Scale Factor differential pressure 8msb

Byte8: Scale Factor differential pressure 8lsb

Byte9: CRC

After

a

start

continuous

measurement

commands, the measurement results can be

read out.

The temperature and scale factor don’t need to

be read out (every time). The read sequence

can be aborted by a NACK and a STOP

condition.

5.3.2 Stop Continuous Measurement

Command

Command code (Hex)

Description

Stop continuous

measurement

0x3FF9

This

command

stops

the

continuous

measurement. It powers off the heater and

makes the sensor receptive for another

command.

The Stop command is also required when

switching

between

different

continuous

measurement commands.

When the sensor is in continuous measurement mode, the sensor must be stopped before it can accept another command.

The only exception is the soft reset command as described in section 5.3.5. In idle mode the sensor will consume less power.