What is the difference between IMS20-B and IMS20-D?

The IMS20-B has no built-in display — it transmits measurement data via electrical output only (RS-485, 4–20 mA, or 0–10 V). The IMS20-D adds a 2.7" e-ink display that shows current humidity and temperature readings directly on the device. Both variants use identical sensors and have the same measurement accuracy.