Summary

Technical Reprint TR-002

Typical Hydrogen gas sensor locations in a semiconductor manufacturing facility include:

•Hydrogen storage areas

•Valves in Hydrogen pipelines

•Furnace area – inlet, outlet, internal tubing

•Off gas ducts

•Return room air ducts

•Cavity between dropped ceiling and the roof (or floor above)

In this plant there are sixteen sensors located within four rooms. Sensors are a catalytic bead type. There are two beads in each sensor element, one of which is activated by a catalyst in the presence of a combustible gas and the other is not. These beads are inserted in a wheatstone bridge circuit and the relative resistance of the beads affects the bridge output in the presence of gas. Changes in temperature and relative humidity have no effect on the output of the circuit since the catalyzed bead and the reference bead are similarly affected and the relative difference in output does not change.

Sensor output is digitalized at the sensor module and transmitted to the controller. Transmitting a digital signal give great tolerance to RFI and EMI effects. In addition it enables diagnostics to be performed at the sensor and be transmitted to the controller along with the concentration measurements. Also, sensor modules are given an address which permits multiplexing multiple sensors on a single wire.

Benefits of Controller Capability. The controller is designed to provide high reliability, ease of operation and data management capability. It is the data management capability that separates the SENTRY controller from other gas monitoring systems. Conventional controllers simply react to events (as a thermostat reacts to temperature reaching a setpoint). To manage a risk it is necessary to use information to formulate a response to leak rather than reacting to an event after an alarm has occurred.

It has already been mentioned that the system configuration is user programmable. This includes alarm levels, calibration procedures, report scheduling and display mode. The low alarm level is set at 10 percent of the LEL and the high alarm level is set at 60 percent of the LEL. A single controller can handle up to eight sensors and four controllers can be mounted in a standard 19 inch instrumentation rack. The controller displays the sensor concentration, the gas type, concentration units, and alphanumeric messages.

Reports to Help Decision-Making and Document Due Diligence. The Sentry can provide data to a distributed control system (DCS) via MODBUS or provide reports via a printer. The reports are also available at the display and include status reports, history reports, calibration reports and system configuration reports. This particular customer only needed the printer reports. When the concentration exceeds a user definable limit. The controller prints each key event when it occurs.

This history reports are also very useful in determining if there is any regularity to gas leaks. For example, history reports show the date and time the highest concentration occurred in the period. The frequency for the period can be programmed on an hourly, shift, or daily basis. As one semiconductor facility one sensor recorded its highest concentration at the time every day. After investigation it was found that a purging of a Hydrogen furnace was releasing Hydrogen into the room. The purging procedure was changed and release of Hydrogen into the room stopped. Daily history reports also provide good documentation to confirm the facility’s safe operating procedure if legal action was brought against the company. In today’s legal environment, such documentation is essential to minimize liability. In addition to the alarm indication at the controller, the facility has an annunciator panel located near a security area. The panel displays each combustible and toxic gas sensor in alarm.

Gas risk management requires a comprehensive look at the hazards of gas leaks. Properly designed gas monitoring systems provide suitable hardware in combination with data management and diagnostics capability to custom-fit a solution for managing, rather than reacting to, gas leaks.

Sierra Monitor Corp. 1991 Tarob Ct., Milpitas, California 95035 USA 408-262-6611, 800-727-4377 FAX: 408-262-9042

Visit our Web Site at: http://www.sierramonitor.comE-Mail: sales@sierramonitor.com Rev. A1

TR-002 specifications

Sierra Monitor Corporation's TR-002 is an advanced wireless monitoring device designed for various industrial and commercial applications. This versatile device excels in providing comprehensive environmental monitoring and control, ensuring safety, efficiency, and compliance with regulations.

One of the standout features of the TR-002 is its robust sensor capabilities. The device is equipped with multiple sensors capable of detecting gases, temperatures, humidity levels, and other environmental parameters. This multi-sensor approach allows users to monitor a range of conditions in real-time, facilitating proactive management of their facilities.

The TR-002 employs cutting-edge wireless communication technology, enabling seamless integration into existing networks. It supports several communication protocols such as LoRa, Zigbee, and Wi-Fi, ensuring flexibility in deployment. This wireless capability allows for easy installation in hard-to-reach areas without the need for extensive wiring, saving time and resources.

Additionally, the TR-002 boasts a user-friendly interface, providing operators with intuitive access to data and analytics. The device's dashboard allows users to visualize real-time readings and historical trends, aiding in informed decision-making. Alarm notifications and alerts can be configured to notify personnel of any anomalies, thereby enhancing safety protocols.

The TR-002 is designed with durability in mind, featuring an industrial-grade enclosure that protects against harsh environmental conditions. This rugged construction makes it suitable for various applications, including manufacturing plants, warehouses, and outdoor environments.

Another significant characteristic of the TR-002 is its scalability. Whether monitoring a single location or managing multiple sites, the device can be easily expanded and adapted to meet the growing needs of a facility. This scalability is complemented by a cloud-based data management system that allows for centralized monitoring and control from anywhere in the world.

In conclusion, Sierra Monitor Corporation's TR-002 is a state-of-the-art wireless monitoring solution that combines advanced sensing technology with flexible communication options. Its durability, user-friendly interface, and scalability make it an invaluable asset for organizations looking to enhance their monitoring capabilities, ensure safety, and optimize operational efficiency. With the TR-002, businesses can take proactive steps towards maintaining ideal environmental conditions and compliance with industry standards.