Most OEM pressure cells hand the host a raw bridge signal, then every firmware team repeats the same work: amplification, digitization, temperature correction. The KELLER 9LD ends that loop by embedding a DSP core inside a 19 mm x 5 mm stainless housing, so the microcontroller reads finished 16-bit pressure and temperature values over I2C.

What do I do when my battery budget cannot afford a conventional transmitter?

A conventional amplified transmitter draws milliamps continuously. The 9LD sleeps at roughly 100 nA and wakes for a conversion at about 1.5 mA lasting under 8 ms, which is why it anchors KELLER Pressure AG in the battery-operated D-line for IoT sensing. Supply tolerance of 1.8 to 3.6 VDC means a single lithium cell works directly, with no regulator stage burning the reserve.

How does chip-in-oil change the accuracy conversation?

KELLER Pressure AG fills the silicone oil behind the 316L diaphragm around the sensing chip itself, so temperature compensation happens at the source instead of in external electronics. The result is 0.15% FS accuracy with a total error band of 0.7% FS across -10 to 80 deg C, and more than 10 million pressure cycles of endurance. Compared with the analog 9LC sibling that outputs a ratiometric 0.5 to 4.5 V signal, the 9LD trades the analog interface for digital noise immunity and dual pressure-plus-temperature output; engineers who need a plain voltage output for legacy capture hardware stay with the 9LC, while new microcontroller-based designs integrate the 9LD with two wires and no calibration step.