enDAQ Sensor Product Selection
There are many different variants of our sensors, we recognize that it can be difficult sometimes to select the one that's best for your application! If you're not sure, don't hesitate to reach out and ask for help! In general, we recommend the S2-D40D200 as our most versatile product due to its wide bandwidth, measurement range, and affordability.
In this Article
Our sensor naming and part numbering are one-in-the-same. We used to have complicated and long part numbers in addition to a product name: Slam Stick C, X, or S. Our customers found this confusing, as did we! Now are calling our products what they are: sensors. And we are adopting what luxury car companies do; they have the product model be the same thing as its name!
Our sensor names/numbers describe the device from the outside in:
- The sensor family or series
- The form factor within that series
- The main accelerometer type and range
- The secondary accelerometer type and range.
Here's a graphic that helps illustrate this naming convention.
There will be some confusion in the first few months of our new website and naming convention. Hopefully, as the old products get discontinued and new ones introduced it will become clearer. In the meantime don't hesitate to reach out and ask us for some clarification!
Common Elements of All Sensors
There are many common embedded sensors to every enDAQ sensors. These include:
- Orientation (gyroscope, magnetometer & another accelerometer)
- External temperature
- External pressure
- External humidity
- External light
- Internal temperature
- Internal pressure
By external, this specifies a sensor on the membrane/control pad (external graphical sticker). More information on the specific sensors and their characteristics are available in this article.
There is currently just one over-arching product family: the S-Series, S for sensor. But by the end of 2019 we will have introduced our WiFi enabled devices that will be called the W-Series.
The number in the series name/type defines the form factor:
- S1: polycarbonate mini (0.76" shorter than the S3/S4)
- S2: aluminum mini
- S3: polycarbonate enclosure
- S4: aluminum enclosure
- This also has the largest battery of 250 mAh, the other types have a 200 mAh battery. Here is an article on battery performance.
Selecting Aluminum vs Polycarbonate
The enclosure material has two significant impacts:
- Stiffness: Our sensors are primarily an accelerometer. As such, an accelerometer's own internal resonance will limit the frequency range it can accurately measure before its own resonance starts influencing and amplifying the vibration in the environment and becomes invalid. The aluminum enclosure is much stiffer and therefore increases the bandwidth from up to 1,000 Hz in the polycarbonate enclosure to 2,000 Hz in the aluminum enclosure.
- Robustness: The aluminum enclosure is obviously more robust than the polycarbonate enclosure. If your device will be handled repeatedly with frequent mounting and dismounting and potentially subjected to occasional direct impacts, the aluminum enclosure may be the better option.
For more information on the different enclosures are available in this article.
Shock vs Vibration
All of our sensors include two accelerometers to provide the dynamic range and be useful in measuring both shock and vibration data; but some are better than others for the different interest areas. To help you select the right accelerometer, explained more below, we provided a filter to select what you are most interested in:
The 25g piezoelectric accelerometer or the 8g capacitive (both digital or analog) are recommended for applications when vibration is the highest concern. These accelerometers offer the lowest noise and highest resolution.
The piezoresistive accelerometer is definitely best for shock testing but we recognize that it comes with a higher price point. The 500g or 2,000g piezoelectric accelerometers are also good for some shock testing although high-frequency events can cause the accelerometer to saturate which is why we recommend piezoresistive generally.
Both Shock & Vibration!
Again, all sensors have the ability to measure both shock and vibration; but the sensors with either the 100g piezoelectric or 40g capacitive are the most versatile and also the most popular for customers who are unsure of their environment.
What type of accelerometer do I need?
This is admittedly a complicated question to answer. For more information on accelerometer types and what’s best for your application refer to our blog post on Accelerometer Selection. But to summarize, there are three types:
- Variable Capacitance: Best for lower frequency (<500 Hz) vibration and some shock if only limited shock information is needed.
- Piezoelectric: Best for vibration with its high sensitivity, but can capture shock as well. It can experience saturation events when experiencing shock events outside its measurement range however and it is not DC-coupled (can't measure static accelerations or vibrations less than 5 Hz). More information is available on the piezoelectric accelerometer blog.
- Piezoresistive: Best for high-end shock testing, does not experience saturation from out-of-range events and it is DC coupled (can measure low frequency and static). Has a higher price point, however.
What measurement range do I need?
The measurement range is inversely proportional to resolution and noise. Meaning that as you increase the range of accelerations the device can measure, the noise levels increase and the smallest unit of measure also increases. If you buy a unit and within the first test or two realize that you would rather have a wider measurement range or better resolution, we can exchange the unit for no cost. More information on the specific sensors and their characteristics are available in this article.
Price vs Data Quality
We have a range of products that have a lot of overlap in general functionality. But as the above discussions explained, the differences matter when it comes to the type of data recorded. Often though, with better quality comes higher costs and prices. We aim to make all our products affordable yet of high quality, but within our product line there are still some tradeoffs. If cost is a primary driver for you or your organization we recommend sensors with digital capacitive accelerometers. If you are in need of something even more affordable, check out some lower-priced competitors discussed here.
Old Part Numbers Mapped to New
As mentioned above our old part numbers were long and confusing! They have been replaced by part numbers that describe the product from the outside-in (as the customer sees it), not from the inside-out (as we had seen it). Our product naming convention has also been dropped and replaced by more simple part numbers that will double as names, much in the same way as luxury car companies.
The new part numbers and names will coincide with an updated design of the products which will include a better secondary accelerometer, more storage, and advanced firmware capabilities. Some of these new products aren't available yet are designated in italics.
|Old Number & Name||Primary Accelerometer||New Number & Name|
|Slam Stick C (LOG-0003)|| Digital Capacitive
|| S3-D16, S3-D40, S4-D40
S1-D40D200 & S2-D40D200
|Slam Stick X Polycarbonate (LOG-0002-PC)|| Piezoelectric
||S3-E25D40 & S3-E100D40|
|Slam Stick X Aluminum (LOG-0002-AL)|| Piezoelectric
||S4-E25D40 & S4-E100D40|
|Slam Stick S (LOG-0004)|| Piezoresistive
||S4-R500D40 & S4-R2000D40|