Oldham BM 25A Transportable Multi-Gas Area Monitor

Overview

The Oldham BM 25A is a transportable multi-gas area monitor from Teledyne Gas and Flame Detection. Teledyne describes it as packing the benefits of a fixed system area monitor into a rugged, user-friendly and transportable instrument. The Oldham BM 25A detects one to five gases at the same time and is intended for mobile or temporary work, team protection, area surveillance and places where fixed detection is not practical. It weighs about 6.8 kg (15 lb), has a carrying handle and a 360 degree beacon, and is available in a standard version and a wireless version, the BM 25A Wireless, that forms a self-healing mesh network.

Seven Star LLC supplies the Oldham BM 25A, its sensors, chargers and the MX 40 wireless controller to oil and gas operators, refineries, contractors, shutdown and turnaround teams, tank cleaning crews and utilities in Oman and the GCC. Our Muscat team helps configure the gases and network size, and we provide model selection support from Muscat.

Key Features of the Oldham BM 25A

• Up to five gases simultaneously: catalytic, infrared, electrochemical and photo-ionisation sensor options.
• Loud, visible alarm: 103 dB audible alarm and an ultra-bright LED beacon visible through 360 degrees.
• Long runtime: NiMH battery for up to 170 hours of operation, or 135 hours in wireless mode, with a full recharge in about 4.5 hours.
• Long-term monitoring: an intrinsically safe trickle charger supports extended monitoring in classified zones.
• Rugged case: impact-resistant polycarbonate, IP66.
• Data logging: 200,000 measurements, more than four months for a five-gas configuration, with STEL and TWA values available.
• Graphic backlit display for gas readings and status.

Sensors and Measuring Ranges

According to the Teledyne brochure, the Oldham BM 25A measures explosive gases from 0 to 100 percent LEL with a catalytic sensor at 1 percent resolution, and methane, propane, butane, isobutane, LPG, ethanol and pentane from 0 to 100 percent LEL with infrared sensors; methane is also available from 0 to 100 percent volume by infrared. Oxygen is measured from 0 to 30 percent volume at 0.1 percent resolution. Electrochemical toxic sensors include carbon monoxide (0-100 or 0-1000 ppm), hydrogen sulfide (0-100 ppm), hydrogen (0-2000 ppm), sulfur dioxide (0-30 ppm), chlorine (0-10 ppm), nitrogen dioxide (0-30 ppm), nitric oxide (0-300 ppm), hydrogen chloride and hydrogen cyanide (0-30 ppm), ammonia (0-100 or 0-1000 ppm), phosphine, arsine, ozone, phosgene and hydrazine (0-1 ppm), silane (0-50 ppm), ethylene oxide (0-30 ppm), hydrogen fluoride (0-10 ppm) and chlorine dioxide (0-3 ppm). Carbon dioxide is measured from 0 to 5 percent volume by infrared, and VOCs as isobutylene from 0 to 1500 ppm with a PID sensor.

Wireless Mesh Network

The optional radio allows several Oldham BM 25A units to communicate on one network or to send data to a controller. Teledyne lists 2.4 GHz, 100 mW IEEE 802.15.4 radio, up to 30 devices per network and up to 16 independent networks without interference, with a communication distance of about 0.6 mile line of sight between two units. The mesh has no central hierarchy: each node can send, receive and relay data, and if a node fails the data takes another route. When a unit goes into gas alarm, every unit in the network reports a corresponding alarm transfer, so a whole work team is warned. If the network splits, each unit still alarms locally, and when the obstacle is removed the groups merge again automatically.

The SmartWireless MX 40 controller gives an operator interface to the network. It handles up to 32 wired or wireless devices including up to 16 BM 25A units, is packaged in a NEMA 4X enclosure, can be configured for up to eight zones, and displays device location, alarm status, gas reading, battery life and signal strength, with SD card data logging. Command functions include alarm reset, acknowledge, test and radio silence, and Oldham addressable I/O modules add 4-20 mA inputs and outputs, relay outputs and contact inputs.

Certifications

The Oldham BM 25A is certified to ATEX and IECEx. The standard version without an IR sensor carries II 2G / I M1 marking with Ex db ia IIC T4 Gb protection, and versions with an IR sensor carry II 2G / I M2. The wireless BM 25 AW has equivalent markings, and INMETRO versions are also listed with an ambient range of −20 to +55°C. Always check the marking of the supplied unit against the area classification.

Applications of the Oldham BM 25A

• Perimeter monitoring during plant shutdowns, turnarounds and hot work.
• Tank cleaning, vessel entry and confined space support around the entry point.
• Temporary coverage when a fixed detector is out of service.
• Pipeline tie-ins, well intervention and drilling site perimeters.
• Utility tunnels and excavations with H2S, CO or oxygen deficiency risks.

An Oldham BM 25A complements permanent detection such as the Oldham OLCT 100 and the Oldham OLCT 710, which feed controllers like the Oldham MX 62 in permanent installations.

Deployment Tips (General Guidance)

This guidance is general practice rather than Teledyne data. Place each Oldham BM 25A between the potential leak source and the workers, at a height suited to the gas density, and away from obstructions that block the beacon. Bump test before each deployment, record the results in the instrument log, calibrate at the intervals in the user manual, and keep batteries charged between jobs. When using the wireless Oldham BM 25A, check signal quality on site, because steel structures and tanks can shorten the line-of-sight range.

Technical Specifications

How to Order

To order the Oldham BM 25A, send Seven Star LLC the gases and ranges you need, the number of units, whether you need the wireless version and MX 40 controller, and your charging arrangements. Our Muscat team will prepare a formal quotation. The Teledyne brochure and ATEX user manual can be downloaded from this page, and we provide model selection support from Muscat for customers across Oman and the GCC.