Brooks SLA7840AZ635 is a configured SLA7840 high-purity, all-metal-sealed digital remote-transducer pressure/flow controller. It regulates gas pressure from an external transducer signal while measuring mass flow through an integral thermal sensor. The SLA7840A prefix identifies the analog-I/O version. Published SLA7840 documentation does not define the remaining Z635 suffix; gas, full-scale flow, process connection, valve arrangement and calibration remain configuration-specific
Configurations vary. Verify the exact unit before choosing a replacement.
Nickel internal/external seals; standard 316L stainless-steel valve seat
Wetted surface finish
32 µin Ra maximum
Ratings
Leak integrity
1 × 10^-10 atm·scc/s helium maximum, inboard to outboard
Environment
Operating ambient temperature
0–60 °C (32–140 °F)
Fluid temperature
0–65 °C (32–149 °F)
What Does SLA7840AZ635 Mean?
Only the base model and analog-interface letter are defined by available Brooks documentation.
Segment
Field
Interpretation
SLA7840
Base model
High-purity, metal-sealed digital remote-transducer pressure/flow controller.
A
I/O version
Analog I/O with a 15-pin D-connector, 0–5 VDC setpoint and flow signals, and +15 VDC power.
Z635
Remaining suffix
Not defined in published SLA7840 documentation. Do not assert a gas, range, fitting, valve or special option from these characters without a nameplate, calibration sheet or Brooks order record.
Remote-Transducer Operation
A user-supplied pressure transducer monitors the controlled vessel or line. The SLA7840 compares that pressure signal with the setpoint and adjusts its integral solenoid valve to stabilize pressure. Its integral thermal mass-flow sensor simultaneously produces a signal proportional to flow through the valve.
