Brandt Instuments Representing Otis Instruments Fixed Gas Detection Systems, wired and wireless sensor assembly
                    Brandt Instruments Representing Otis Instruments

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Otis Instruments OI-7400
Wired Remote Sensor Controller Systems

Fixed Gas Detection System
Choose From 2-32 Channel Controller Monitors

home otis instruments fixed point detectors OI-7400 Series Otis Instruments Multi-Channel Wired Sensor Controller System


OI-7420 2-Channel Controller-Monitor with Lights & Horn

2 Channel Controller- Monitor
Configured with Optional Light & Horn




Otis Instruments 1-12 Channel Controller Monitor

1 to 12 Channel Controller-Monitor



Otis Instrumets OI-7432 32-Channel Controller Monitor for Remote Sensor Heads

32 Channel Modbus Controller - Monitor


Otis Instruments OI-7400 ProSafe series wired controller systems are available as 2 to 32 channel controllers as part of a fixed gas detection system.  OI-7400 systems are designed to provide continuous monitoring for a variety of common atmospheric hazards including:

Ammonia (NH3) Formaldehyde (CH2O) Oxygen (O2)
Carbon monoxide (CO) Hydrogen Cyanide (HCN) Ozone (O2)
Chlorine (Cl2) Hydrogen Fluoride (HF) Sulfur dioxide (SO2)
Combustible gas (LEL) Hydrogen Sulfide (H2S) Phosphine (PH3)
Fluorine (F2) Nitrogen Dioxide (NO2) PID sensor for VOC detection & many others

OI-7400 controller systems are avalailable for a variety of of applications. The OI-7420 with two channels can be used in smaller locations such as warehouses and laboratories.  The OI-7432 with 32 channels and a Modbus interface is perfect for installations such as large parking garages where the Modbus interface saves money in wiring the remote sensor head assemblies.

OI-7420 ProSafe 4x2 Wired (4-20mA) 2 channels, 4 dry contacts
OI-7440 ProSafe 4x4 Wired (4-20mA) 1-4 channels, 4 dry contacts
OI-7480 ProSafe 4x8 Wired (4-20mA) 8 or 12 channels, 4 dry contacts
OI-7432 ProSafe 4x32 Wired (ModBus Interface only) 32-channels, 4 dry contacts

The compatible OI-6000 wired sensor assemblies are available with Electro-Chemical (EC), Catalytic Bead, PID or Infrared (IR) sensor elements.  Sensors assemblies are linked by wire to the controller.  The the OI-7400 offers the flexibility to choose single, twin or tri-color high-intensity strobes. For instance, it an be configured with a TriLite strobe, integrated 102 db audio alarm, combined with a real time LCD readout…..all in a sleek, tough NEMA 4X housing.

The ability to display data and activate alarms in relation to readings sent from on-site sensors make the OI-7400 controllers an efficient way to monitor toxic hazards.  With four dry contact relays, signals can also be routed to and from other remote sensors such as temperature, pressure, tank levels, motors and fans.


OI-7400 ProSafe Wired Controller Systems
General Technical Specifications

Note: Specifications below are common to all 7400 controllers
For specific models download the literature using the links below.


Stahlin fiberglass with clear window, wall mount

NEMA 4 enclosures are intended for indoor and outdoor use primarily to provide a degree of protection against corrosion, windblown dust and rain, splashing water, and hose-directed water; and to be undamaged by the formation of ice on the enclosure.

Dimensions & Weights OI-7420:  8" x 8" x 4" | 8.15 lbs
OI-7440: 10" x 8" x 6" | 8.5 lbs
OI-7480: 12" x 10" x 6" | 12.5 lbs
OI-7432: 10" x 8" x 6" | 8.5 lbs
Display Graphical LCD, sunlight readable
LED back-light, 160 x 104 resolution
Tamb Temperature Range (-4F to +158F) (-20C to +70C)
Interface OI-7420: Four push buttons (MENU, ADD, SUB, RESET)
OI-7440: 5 Push-Buttons (MENU, ADD, SUB, SCAN/HOLD, and RESET/ESC
OI-7480: 5 Push-Buttons (MENU, ADD, SUB, SCAN/HOLD, and RESET/ESC
OI-7432: 5 Push-Buttons (MENU, ADD, SUB, SCAN/HOLD, and RESET/ESC
Sensor Types Electro-chemical, catalytic bead, PID or Infrared.
Product Compatibility Any Otis Wired Sensor Assemblies (OI-675, OI-6000, OI-6000K)
Other 3rd-Party Wired (Analog) Sensors
Power Supply OI-7432: 6.25A (150W), 85/264V AC to 24V DC (Optional)
Operating Voltage 12-35 VDC | Optional AC Power Supply
Current Draw 7420: 225 mA Maximum
7440: 275 mA Maximum
7480: 300 mA Maximum (8-Channel), 25 mA Maximum (12-Channel)
7432: 275 mA Maximum
Input Signal 4-20mA, analog inputs
(Internal Alarm Power)

7420: 12-35 VDC (Fault Indicator) RS-485 Modbus
7440: 12-35 VDC (Fault Indicator) RS-485 Modbus with optional real-time monitoring software
7480: 4-20 mA (Fault Indicator), RS-485 Modbus with optional real-time monitoring software
7032: RS-485 Modbus only

Relays 4 Dry-Contact Relays with 4 Amp Replaceable Fuses
Fault Terminal
Option to Disable Alarm Relays
Latching and Non-Latching Relay Settings
Individual Set Per Channel
Protection Power Electromagnetic Interference (EMI) Filter
4-20 mA Surge Suppression
RS-485 Surge
Warranty Hardware: One year (Limited)
Part Number Formula

OI-7420-[Power]-2 | OI-7420-X-2
OI-7440-[Power]-4 | OI-7440-X-4
OI-7480-[Power]-[Channels] | OI-7480-X-X
OI-7432-[Power]-32 | OI-7432-X-32

Each OI-7400 monitors includes the controller with all standard alarms, relays and electronics installed in a non explosion-proof fiberglass housing. Custom configurations with lights and horns are available.

Note: Cable, conduit, wire and other components necessary to connect remotely located sensors with the controller are not included. Order any cable separately from Otis or an electrical supply house.

    Otis OI-7420 ProSafe Controller Data Sheet    Manual

   Otis OI-7440 ProSafe Controller Data Sheet    Manual

   Otis OI-7440-R-WireFree-Converter-Configuration-Guide

   Otis OI-7480 ProSafe Controller Data Sheet    Manual

   Otis OI-7432 ProSafe Controller DataSheet   Manual

For additional accessories & options:  Accessories


Otis Instruments OI-7432 ProSafe Wired Controller Monitor Panel Front Diagram

OI-7432 ProSafe Wired Controller-Monitor
Typical Example of the Panel Front of OI-7400 Series

  Otis Instruments OI-6000 Sensor Assembly Sensors

Part # Description Range Resolution
OI-254-O2 O2, Oxygen 0 - 25% vol 0.1%
± 2%
OI-2018-SB-CB2 LEL, Combustible Gas
(Catalytic Bead) (OI-6000 only)
0 - 100% LEL 1.0% Increments
OI-140-IR-LEL LEL, Combustible Gas (Infrared)
(OI_6000 only)
0 - 100% LEL 1.0% Increments
± 2%
OI-254-CO CO, Carbon Monoxide 0 - 1000 ppm 0.1 to 10 ppm, 1 ppm thereafter
± 2%
OI-140-IR-CO2 CO2, Carbon Dioxide
(OI-6000 only)
0 - 5% vol 0.1 ppm
± 2%
OI-254-H2S H2S,  Hydrogen Sulfide 0 - 100 ppm 0.1 to 10 ppm, 1 ppm thereafter
± 2%
OI-254-H2S-2K H2S, Hydrogen Sulfide (Ext.Temp) 0 - 2000 ppm 0.1 to 10 ppm, 1 ppm thereafter
± 2%
OI-254-NH3 NH3, Ammonia 0 - 100 ppm 0.1 to 10 ppm, 1 ppm thereafter
± 5%
OI-254-NH3A-N NH3, Ammonia (Ext) 0 - 1000 ppm 0.1 to 10 ppm, 1 ppm thereafter
± 5%
OI-254-Cl2 Cl2, Chlorine 0 - 10 ppm 0.1 ppm
± 5%
OI-254-F2 F2, Florine (Call for availability) 0-1 ppm 0.01 ppm
± 5%
OI-254-CH2O CH2O, Formaldeyde 0-10 ppm 0.01 ppm
± 2%
OI-254-H2 H2, Hydrogen 0- 4% vol 0.1 ppm
± 10%
OI-254-HCL-A HCL, Hydrogen Chloride 0- 100 ppm 0.1 ppm
± 5%
OI-254-HCN-2 HCN, Hydrogen Cyanide 0- 100 ppm 0.1 ppm
± 5%
OI-254-HF HF, Hydrogen Floride 0 - 10 ppm 0.1 ppm
± 10%
OI-254-NO2-N NO2, Nitrogen Dioxide 0-50 ppm 0.1 ppm
± 5%
OI-254-O3 O3, Ozone 0-100 ppm .1 to 10 ppm, 1 ppm thereafter
± 2%
OI-254-SO2 SO2, Sulfur Dioxide 0 - 20 ppm .1 to 10 ppm, 1 ppm thereafter
± 2%
OI-254-PH3-5-5 PH3, Phosphine 0 - 5 ppm 0.1 ppm
± 2%
OI-PID-A1 PID, Photo Ionization Detector for volatile organic compounds (VOCs) 0-2000 ppm 0.1 to 10 ppm, 1 ppm thereafter
± 5%
OI-254-AH PID, Photo Ionization Detector for volatile organic compounds (VOCs)

0-50 ppm

0.1 to 10 ppm, 1 ppm thereafter
± 3%
Note: Other gases and ranges available. Contact us for additional information


WARNING! Otis Instruments equipment should only be used in conjunction with the manufacturer's instructions.
Failure to follow such instructions could result in serious injury or fatalities.


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    Prairieville, LA  70769 
Phone: 225-673-6776
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