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The RFM2100 and RFM3200 are indeed very similar. The RFM2100 has an inter-digitated capacitor added to increase its sensitivity to moisture. One way to think about it is that the RFM2100 is a high-sensitivity moisture sensor with less dynamic range and the RFM3200 is a low-sensitivity moisture sensor with more dynamic range.
Given the time your post came in, I am assuming that you are interested in operating in Europe in the narrow ETSI band. S3 has a big advantage over S2 in the ETSI band because the resolution at a given frequency is much better than S2. In the wide North America FCC band, the sensor can be read at many channels, so the S2 resolution can approach that of the S3 through post-processing.
Because of the very large range of applications involving moisture, testing is the best way to work out the best sensor to use. So your plan looks good.0
The marketing messaging can make this a little difficult. With the exception of the RFM3240, all of our sensors have the adaptive frontend enabling moisture sensing. An S3 is an S2 with added temperature sensing plus improvements in a number of areas. The RFM3240 is the exception because the adaptive frontend is not present on the chip, so it cannot measure moisture.
The S3-based sensors that can measure both moisture and temperature are the RFM3200, RFM3250, and RFM3254. The RFM3260 is not practical as a moisture sensor because the antenna is protected within the plastic housing.
The amount of sensor code movement varies from sensor to sensor depending on the amount of water present and the location of the water. The water detunes the antenna and the adaptive frontend adjusts to compensate, leading to the detection of moisture. Since every antenna behaves a little differently, the moisture sensitivity varies with the antenna design. The sensitivity of the sensor code movement also varies with the location of the water on the antenna since some areas are far more sensitive than others.0
The details for reading sensor codes are in our app note “Reading Magnus-S Sensors Application Note”, and it can be downloaded from the “Tools and Training” area. If you have not read this, then this is the best place to start. There is sample ThingMagic code there. If you have read this, then we’ll have to dig in a little more.0
There is a brochure at http://rfmicron.com/rfm2100-wireless-flexible-moisture-sensor/ that shows sensor code movement for two different methods of exposing the sensor to water. For simple testing, you should see very good code movement if you put 1/2 drop of water directly onto the interdigitated finger structure.0
I’m sorry we missed your post. We do not have any experience with SkyeTek readers, so we cannot offer any specific advice. Has the problem been resolved?0
We have not developed an annular sensor, so we have no product to offer in that space.0
ThingMagic and NordicID readers have the best compatibility with our sensors. Many readers from other manufacturers have good compatibility, but we are not able to fully check out the very wide variety of readers available on the market. Alien readers at the time of this writing do not support reading our sensor codes.0
The moisture sensors detect liquid water rather than water vapor, a gas, so the sensor codes will not move based on changes in humidity. The amount of liquid water detected depends on the sensor type and where the water touches the sensors. For example, the RFM2110 can detect >0.05 ml of water for most areas of the sensor.0
Incontinence in general is a very big issue, and we have a lot of interest in helping to alleviate its consequences. Our technology is passive, so it cannot issue an alert. It can detect incontinence when a caregiver takes a reading with a handheld RFID reader, so our technology is appropriate for facilities with nurses that make rounds checking on the status of residents. We have seen battery-powered solutions that can issue alerts, and this technology may work in the described use scenario.0
The on-chip RSSI code shows the strength of the reader’s signal as received by the sensor. The RSSI number reported by the reader is the strength of the sensor’s backscattered signal as received by the reader. The two together cover both paths: from the reader to the sensor, and from the sensor to the reader.
Sensor codes can be pulled to lower values for high on-chip RSSI values. Reading the on-chip RSSI value lets you know if the power levels are high enough to affect the sensor code. For best accuracy in the sensor codes, on-chip RSSI values should be kept below about 20. This limit can be implemented by the distance from the sensor to the reader, the reader output power, and by using a SELECT command to tell the sensors not to respond to the reader if the on-chip RSSI code is too high. Under software control, the reader power can be adjusted such that the user does not have to be aware of the on-chip RSSI.1+
We were not able to get Impinj readers to read the temperature codes due to issues with SELECT commands, but maybe they have updated their firmware since our tests. What reader model are you using, and what versions of the firmware and Octane API are being used?1+