Hydrogen Gas Detector, Mark4 - Dual Relay

Arrgh!! Hydrogen Gas Detector

3 Options:

099140 HGD-DR Mark4 AC Dual Relay, 85- 265 VAC 50/60HZ

099141 HGD-DR Mark4 DC Dual Relay, 17-60 VDC

099142 HGD-DR Mark4 VDC, Dual Relay, 12 VDC only


For lead-acid battery charging rooms and other areas where hydrogen is present protects life, property and profits.

Lead-acid batteries on charge emit hydrogen gas after reaching the 80% recharge point.

Automatic Operation, Continuous Monitoring, High Sensitivity & Stability, Solid State Reliability, Safe, 12 Volt dc Operating Voltage, Easy Installation, Low Cost, Two Year Warranty.

The sensor consists of a semiconductor whose electrical conductivity increases when hydrogen is adsorbed on its surface. Conductivity, proportional to the gas concentration, is continuously measured by an electronic circuit.


Typical hydrogen emissions for motive-power batteries are:
Battery Size Hydrogen Gas
12 Volt / 500 Ampere-Hour 3.5 Cubic Feet Per Hour
24 Volt / 720 Ampere-Hour 10.1 Cubic Feet Per Hour
36 Volt / 935 Ampere-Hour 19.8 Cubic Feet Per Hour
48 Volt / 850 Ampere-Hour 23.9 Cubic Feet Per Hour
  Concentrations of 4.1% to 75% mixed with air can be explosive. Sparks or hot surfaces can ignite them. An Arrgh!! hydrogen gas detector in your battery room will provide a warning and facilitate dissipation of hydrogen concentrations before they reach the lower explosive limit (LEL) of 4.1%.

Available Accessories:

» Steel junction box for hard-wiring to wall or ceiling.

Remote box (modular jack with duplicate LEDs, test button, and buzzer if needed) for placement at eye-level or in another room.
» Telephone-type modular cable for connecting the remote box to the detector.
Dimensions: Height 7 " (17.8 cm.)
  Width 4-3/4 " (12.0 cm.)
  Depth 2-1/2 " ( 5.5 cm.)
Mounting: Four 3/16 " (4.5 mm.) screws
Power Requirements: 120 volts ac 50/60 hertz standard.
  220 volts ac, or 12 to 48 volts dc upon request.
Relay(s): Form A, Normally-Open standard.
  Form B, Normally-Closed upon request.
  Form C, Available at additional cost.
Operating Temperature: 14 to 104 degrees F ( -10 to 40 degrees C)