Hydrogen Sensors

HydroKnowz™ gas monitors comprise of an HCMOS microcontroller, a catalytic gas sensing element and amplifier, a semiconductor temperature sensor, a bi-color indicator LED and various optional signaling devices such as an alarm beeper, dry relay and D-to-A converter (or 4-20mA loop driver). Standard devices operate with 3VDC regulated input power. Wide input supply versions are available that accept 6-40VDC (or 6-55VDC). A one-wire bi-directional digital interface (PKPort™) may be used for set-up, calibration and remote monitoring via a PC.

 

Each time that power is applied the device enters a brief warm-up state after which active gas sensing functions commence. Gas concentrations and sensing state indications become available after the warm-up period has elapsed. Gas sensor signals are continuously sampled by an 8-bit A-D subsystem and are digitally filtered to reject burst noise and other spurious events. The filtered signal is then stripped of its baseline component and is spanned according to its memory-resident calibration values. The scaled signal is used to produce linear readings of gas concentration that may be accessed in real-time via the utput signal DAC, 4-20mA driver, or the PKPort™ interface.

 

  • Warning & Alarm Levels
  • Alarm & warning PPMs specified at order time
  • Alarm level from 2,000 to 20,000 ppm
  • Warning level/action is optional
  • Warning level from 20-80% of alarm level
  • Levels are field-adjustable via PK-Port™
  • Calibration
  • All devices individually calibrated
  • FLASH-based calib. accessible via PK-Port
  • Periodic factory recertification avail.
  • State Indications
  • Normal, warning, alarm & error state
  • Bi-color LED indicates all states
  • Optional beeper for alarm & error indication
  • Errors-as-Alarms for fail safe operation
  • Warning and/or alarm trigger relay/TTL
  • Live monitoring & data logging via PK-Port
  • Incompatible Uses
  • Not for use in anaerobic environments
  • No dusty or corrosive environments
  • No condensing moisture
  • May be adversely affected by high concentration silicone vapors
  • Reliability Features
  • Audio-visual or alarm-producing errors
  • Sensor failure & disconnection detection
  • Temperature out-of-bounds detection
  • Digital calibration values delimited
  • Low supply voltage inhibit
  • Power fail detect via signal offset loss/relay
  • Watchdog timer & software checksums
  • PK-Port Interface
  • Access via interface connector pin
  • PC (serial) interface module extra
  • Real-time monitoring and data-logging
  • Access/modify config. & cal. values
  • Environmental Requirements
  • Diffusion sampling
  • 3 meters/second flow rate maximum
  • 5% minimum atmospheric oxygen
  • 0% to 99% R.H. (non-condensing) oper.
  • Mechanical
  • Open-frame circuit size: 61 x 48 x 26 mm
  • Aluminum enclosure size: 74 x 82 x 26 mm
  • Open-frame weight: 30 g
  • Enclosed weight: 80 g