ASAHI S670S Series Digital Pressure Regulator Kit (Positive-Pressure, Secondary Pressure Control)

Overview

The ASAHI S670S Series Digital Pressure Regulator Kit is an integrated, DIN 96-mountable secondary pressure control system engineered for high-stability pneumatic regulation in precision laboratory, analytical instrumentation, and semiconductor process environments. Unlike conventional mechanical regulators, the S670S employs closed-loop electronic pressure control based on real-time feedback from a calibrated piezoresistive silicon pressure sensor. It actively modulates a proportional solenoid valve to maintain a user-defined secondary (output) pressure—regardless of fluctuations in primary (inlet) supply pressure or downstream flow demand—within ±1% full-scale accuracy. Designed for dry air applications only, the unit operates at DC 24 V and delivers ultra-low flow output (0–50 nL/min), making it suitable for microfluidic actuation, leak testing calibration, mass flow controller biasing, and vacuum chamber backpressure stabilization where minimal thermal drift and rapid dynamic response (<5 s settling time) are critical.

Key Features

• Integrated digital architecture: Combines pressure sensing, PID-based control logic, proportional valve actuation, and local/remote interface—all within a compact 96×96 mm DIN panel-mount housing.
• Dual-mode pressure setting: Local configuration via front-panel 4-digit thumbwheel switches; remote setpoint modulation via analog input (0–5 V, 0–10 V, or 4–20 mA—selected by model suffix).
• Real-time visual monitoring: High-visibility 4-digit LED display (10 mm character height) simultaneously shows both setpoint and actual secondary pressure with 0.01 kPa resolution.
• Stable low-flow regulation: Optimized for sub-mL/min pneumatic circuits; maintains setpoint integrity even under near-zero flow conditions typical in gas chromatography detector bias lines or MEMS test fixtures.
• Rugged industrial design: Aluminum die-cast chassis, IP20-rated enclosure, and RoHS-compliant construction ensure long-term reliability in controlled lab and cleanroom-adjacent environments.
• Plug-and-play deployment: Requires only DC 24 V power, dry compressed air supply, and two Φ6 push-to-connect fittings—no external controllers or signal conditioners needed.

Sample Compatibility & Compliance

The S670S is validated exclusively for use with oil-free, desiccated compressed air (dew point ≤ −20 °C). It is not rated for corrosive gases, vapors, liquids, or particulate-laden streams. Its internal wetted materials include stainless steel (valve seat), anodized aluminum (body), and fluorosilicone (seals), ensuring compatibility with ISO 8573-1 Class 2:2:2 compressed air quality. The device complies with IEC 61000-6-2 (immunity) and IEC 61000-6-4 (emissions) for industrial environments and carries CE marking per the EU Machinery Directive 2006/42/EC. While not certified to FDA 21 CFR Part 11 or GMP Annex 11, its deterministic analog control loop and absence of non-volatile memory make it suitable for GLP-aligned applications where audit-trail functionality is implemented externally.

Software & Data Management

The S670S operates as a standalone analog control device without embedded firmware, network connectivity, or data logging capability. All configuration and operation occur via hardware interfaces only: front-panel switches and analog voltage/current inputs. This architecture eliminates cybersecurity risks, firmware update dependencies, and software validation overhead—advantageous in regulated QC labs operating under strict change-control protocols. For integration into SCADA or PLC systems, the analog output (if equipped on optional variants) or external pressure transducer feedback may be routed to a validated data acquisition platform supporting 21 CFR Part 11 audit trails. ASAHI provides no proprietary software; configuration documentation aligns with ISO/IEC 17025 clause 5.4.2 for equipment setup verification.

Applications

• Secondary pressure source for capillary electrophoresis and micro-HPLC mobile phase delivery systems.
• Bias pressure control for thermal mass flow meters (MFM) and differential pressure sensors requiring stable reference conditions.
• Calibration station for low-range pressure gauges (0–100 kPa range) and leak detectors (e.g., helium sniffer probe support).
• Pneumatic actuation of precision valves in analytical gas sampling manifolds and environmental monitoring enclosures.
• Backpressure regulation in vacuum deposition chambers during purge cycles to prevent cross-contamination.
• Reference pressure generation for sensor characterization labs validating piezoresistive or capacitive transducers.

FAQ

Is the S670S compatible with nitrogen or other inert gases?
No—ASAHI specifies dry air only. Inert gases may alter sensor calibration stability and void warranty due to unvalidated thermal conductivity and compressibility effects.
Can the unit be mounted vertically or on a vibration-prone surface?
Yes, but orientation must follow the mounting instructions in the manual to avoid condensate accumulation in internal passages; vibration isolation is recommended if RMS acceleration exceeds 0.5 g.
Does the S670S support digital communication protocols such as RS-485 or Modbus?
No—this is an analog-only device. Digital integration requires external analog-to-digital conversion and host-system interpretation.
What maintenance is required over its service life?
Annual verification against NIST-traceable pressure standards is recommended; filter replacement (if installed upstream) every 6 months in non-cleanroom settings.
Is firmware update capability available?
Not applicable—the S670S contains no programmable memory or microcontroller; all functionality is hardwired.