Just reading the spec sheet, Davis would do well to get their transmitter to take I2c and switch over to IDT’s HS 3001. That’s IMO.
But aren't SHT35 and HS3001 pretty much on a par? Actually SHT35 looks better in the 90-100% region. Where would HS3001 score over SHT35?
Not saying there aren't differences - they're just not too obvious from the specs, other than details like 0.1% difference in nominal tolerance which may well get lost anyway in slightly different interpretation of the specs - eg what is the difference between tolerance and accuracy or nominal vs max - and differences in eg binning. And yes Davis would need to move away from Sensibus to modern I2C if these were to be relevant to use in VP2 units.
johnd- After carefully reading through the datasheet of the HS3001, I think you’re correct in your overall thinking. At first, I thought the HS3001 was a more “durable sensor” and it maybe is (when it comes to performance while the sensor is contaminated with dust or debris) but that’s about it. Other than that, it behaves basically the same as the Sensirion sensors. Here is what the HS 3001 datasheet says:
High humidity conditions:
“Important note: The HS300x series sensors are optimized to perform best in the more common temperature and humidity ranges of 10°C to 50°C and 20% RH to 80% RH, respectively. If operated outside of these conditions for extended periods, especially at high humidity levels, the sensors may exhibit an offset. In most cases, this offset is temporary and will gradually disappear once the sensor is returned to normal temperature and humidity conditions. The amount of the shift and the duration of the offset vary depending on the duration of exposure and the severity of the relative humidity and temperature conditions. The time needed for the offset to disappear can also be decreased by using the procedures described in sections 10 and 11.”
“Storage and Handling
Recommendation: Once the sensors are removed from their original packaging, store them in metal-in antistatic bags.
Avoid using polyethylene antistatic bags as they may affect sensor accuracy.
The nominal storage conditions are 10 to 50°C and humidity levels within 20% to 60%RH. If stored outside of these conditions for extended periods of time, the sensor readings may exhibit an offset. The sensor can be reconditioned and brought back to its calibration state by applying the following procedure:
1. Bake at a temperature of 100°C with a humidity < 10%RH for 10 to 12 hours.
2. Rehydrate the sensor at a humidity of 75%RH and a temperature between 20 to 30°C for 12 to 14 hours.”
Soo.... I think the best thing for Davis is to update their transmitter board to take pure I2c and switch to the SHT 35. But even more importantly, be sure that all sensors are packaged correctly.