Pressure measurement: strictly Keller-digital, PA10 digital transmitters never need calibration. TR = pressure TRansmitter = PA10 series RS485 digital pressure transmitter as supplied by Keller in Switzerland. These are state-of-art devices, silicone oil and laser-welded diaphragm isolated, with Hastelloy C276 stainless wetted parts. The company allows its clients to buy just the essentials and thus subsequently design and build their own housings, only one type of pressure transmitter to stock!
Cylinders: strictly machine threaded 316 SS. Communications: strictly RS485, units communicate with computer on primary channel, "talk" to their Kellers on secondary channel. Primary channel: 57,600 baud, secondary: 9,600 baud. Power cycle: 2.5 seconds, pressure transmitters powered up for 0.7 seconds.
They all record their own battery voltage and after more than 10 consecutive bad battery readings disable switching, if device is a switcher, and stop recording.
They all support Hardware Authorization and Debug Output. One box, five functions, two simple flow meters and three switchers, arranged and numbered in increasing complexity from 0 to 4, see 2021 firmware numbers.
