The GPR-35, GPR-2500 SN and GPR-2800 IS/AIS-S are reliable oxygen deficiency monitors for measuring the oxygen concentration in rooms where there is potential for gas leaks to prevent oxygen depletion or asphyxiation and ensure safety of personnel. 
The Analytical Industries' experience in designing precise and reliable oxygen monitors equipped with proprietary oxygen sensors proven in thousands of personal oxygen alarms and diving equipment offer the highest level of protection to the staff that depend on such room oxygen monitors. 
Our oxygen analyzer range also includes oxygen deficiency monitors with remote sensor.


Features of Fixed Ambient Oxygen Deficiency Monitors with Alarms

  • Low maintenance with typically 32 months oxygen sensor life
  • Audible and visual oxygen deficiency alarm available
  • Up to four measurement ranges
  • Accuracy of <2% of span
  • Mains power with battery back-up (GPR-35)
  • Remote oxygen sensor & pump options (GPR-35)
  • Analog output for connection to DCS
  • 12-28 V DC operation (GPR-2500 versions)



Technical Specifications

  GPR-35 GPR-2500-S GPR-2800-IS/AIS-S
Measurement range 0-25% 0-25% 0-25%
Accuracy < 2% of range at constant conditions
Response time T90 < 10 seconds
Sensitivity (LDL) 0.1% O2
Linearity < 1% of scale
Sensor model GPR-11-32-RTS GPR-11-32-4 
XLT-11-24-4 for gases containing >0.5% CO2
Sensor life at 25ºC (77°F) and 1 atm 32 months in air GPR-11-32-4 32 months in air 5°C and 1 atm
XLT-11-24-4 24 months in air 5°C and 1 atm
Calibration interval 30 days
Inlet pressure Atmospheric sampling
Gas connections None
Display 3½ digit LCD; resolution 0.1 LCD 7 x 3.5cm (2.75 x 1.375"); resolution 0.1%
Enclosure Painted aluminum, suitable for indoor use only Fiberglass NEMA 4X Fiberglass NEMA 4X, plus painted aluminum Exd enclosure
Dimensions 10.1 x 22.8 x 7.6cm (4x9x3") 17.1 x 21.3 x 10.8cm (6.75 x 8.375 x 4.25") 25.3 x 40cm (10 x 15.7")
Weight 3.6kg (8lbs) 6.5kg (14.6 lbs)
Compensation Barometric pressure and temperature (GPR-35 and GPR-2800 AIS S)
Temperature (GPR-2500 and GPR-2800 IS S)
Signal output 0-1V 4-20 mA (or 1-5V on GPR-2800 AIS)
Alarms Two adjustable SPDT Form C non-latching relay contacts None Two user-configurable alarms magnetic coil relays rated 3A at 100 V AC (AIS only)
Operating temperature 0°C to 45°C (32°F to 113°F) GPR sensor: 5°C to 45°C (41°F to 113°F)
XLT sensor: -10° to 45°C (14°F to 113°F)
Humidity Non-condensing up to 95% RH
Power 100-240 V AC with battery back-up (battery life up to 30 days or 8 hours in alarm mode) 18-28 V DC 18-24 V DC (IS model)
18-24 V DC or 110 to 220 V AC (ATEX AIS only)
Area classification General purpose CSA/NRTL approved General purpose or with external safety barrier MTL-7706 or equivalent
Ex ia IIB T4 Gb
Tamb -20°C to +50°C
Ex d [ib] ib IIB Gb T4
Tamb -20°C to +45°C