Sensirion Differential Pressure Sensors FAQ

This post will cover some common questions Sensirion has received and answered on their differential pressure sensors.

What is a good o-ring for the SDP800 or SDP806

What o-ring should be used is dependent on the application.

Sensirion most often uses o-rings with the following specification: ID=3.50, W=1.50, Material=NBR.

I get different readings when I compare your sensor with my reference using a membrane-based DP sensor. Is this normal?

It depends on the set-up. Due to the dynamic measurement principle, a small air flow is required. This air flow through the sensor creates a dependence on the tube length. The error is less than 1% with a tube length up to 1 m (with 3/16 inch inside diameter). For more details about this topic, see application note ‘Pressure Drop In Hose Differential Pressure SDP6x0’ in the Download Center.

Keep in mind that the SDP sensor does not depend on absolute pressure and temperature in the same way as a membrane sensor. The application note ‘Selection Guide Differential Pressure Sensor SDP6x0’ can help to understand the advantages of the dynamic measurement principle. Refer to the datasheet for the standard calibration conditions.

Can I use your DP sensors for gases other than air?

The sensor is calibrated for air. If used with other gases, the sensor’s measurement results depends on the thermal properties of the gas compared with air. Note that this also applies to the zero point and temperature compensation.

Please avoid aggressive or etching substances, such as H2O2, NH3, etc.

Are your differential pressure sensors suitable for HVAC applications?

Yes, they are suitable for a wide range of HVAC applications.

​​I need more than one DP sensor in my application. Can I have DP sensors with different I2C addresses?

No, all SDP500 and SDP600 series are produced with the same I2C Address. However, we are able to provide application notes for solutions using I2C multiplexers and how to change the I2C address yourself. Please send an email describing your requirements to support@sensirion.com.​

How can I read the SDP3x laser marking?

The SDP3x is the ‘brand name’ of SDP3x sensor platform. This is why all SDP3x versions (e.g. SDP37, SDP31) have “SDP3x” marked into the housing.

Nevertheless, products can still be identified from the laser marking. This is done by making the digit on the ‘x’ position of SDP3x a prefix of the serial number.

​For example. We have two sensors with the following laser markings:

1: " SDP3 x 2243WP"

2: " SDP3 x 62E878"

Number one is SDP32, and number two is SDP36.

I want to hand solder the SDP1000/SDP2000. Do you have temperature and time recommendations for the soldering process?

For manual soldering, recommend soldering iron temperatures up to 350 °C/662 °F and a soldering time of maximum 3 seconds.

All information was provided by Sensirion Download Center and FAQ .
Sensirion at Digi-key

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