Listed below are some common FAQs we've recently received in regards to sensing technologies/products.
FAQ LibraryCatalytic Bead Point Infrared Open Path Infrared H2S Flame
Catalytic Bead FAQs
What types of Catalytic Bead sensors do you sell?
We offer over 10 different Catalytic Bead Sensor combinations:
They can be supplied in Aluminum or 316 SS material.Standard sensor High temperature sensor Hydrogen specific sensor Poison resistant sensor Super poison resistant sensor CENELEC specific sensor
What temperatures do your sensors meet?
Our standard sensor will go up to 200°F (93°C) and the high temperature sensor is good up to 400°F (200°C, 180°C for European applications).
What is the specified Zero Drift on the GMI sensor?
The drift specification is less than 5% of full scale for 1 year.
What is your typical sensor life?
We state 3-5 years in our literature but we have seen sensors last over 10 years and still function properly. It really depends on the application.
What poisons affect Catalytic Bead Sensors?
– Silicones found in greases and lubricants
– Halides such as Fluorine, Chlorine, Bromine, Iodine
– Heavy Metals such as Tetraethyl Lead will coat or poison the sensor.
What should I use to remote mount and calibrate a sensor?
We recommend our housing #10252 and a Test Gas Applicator #10460-2 or for European applications #B13-020.
What gas do you use for calibration?
We normally use 50% LEL (2.5% by volume) methane in air. The calibration kits consist of a bottle of gas, .4 liter/min regulator, tubing and calibration cup.
Point Infrared
What is the drift specification of the IR2100?
The specification is less than 2% per year.
How do you keep the window from fogging up?
The IR2100 has heaters built into the area near the windows to prevent condensation build-up.
Can I remote mount and remote calibrate the IR2100?
The IR2100 can be remote mounted from the FMD field mounted display. The IR2100 can be remote tested for response operation. It can be remote zeroed but cannot be remote calibrated due to air currents around the sensor. A calibration cup will have to be placed over the sensor head for span calibration.
What is the expected life expectancy of the IR2100?
Since poisons will not affect the IR2100, customers should expect 10 years of life.
Will fog prevent the IR2100 from working properly?
No. We also have rain shields to prevent heavy rains from blocking the IR beams.
What happens when the windows of the IR2100 become dirty?
The IR2100 has an automatic gain adjustment that allows operation up to 70% obscurity on the windows before the output goes to 2mA to indicate dirty windows and beam block.
How many IR2100’s can be connected together using Modbus?
128 up to 247 can be connected together, but it is recommended to connect only 32 units together due to the amount of time to poll the units.
What options are available for the IR2100?
– A FMD field mounted display with option of 3 relays.
– A duct mount kit.
– A flow block for remote sample input.
What do you use to calibrate the IR2100?
We use calibration kit # 31468-1 which consists of a bottle of 50% LEL methane gas in air, a 1 liter/minute regulator, 4 feet of tubing and the metal calibration cup which slides over the end of the IR2100.
Open-Path Infrared FAQ
How and where are IR5000’s normally used?
The IR5000 is used to monitor large areas around spheres, tanks, bullets, pumps, and process equipment containing products which may leak into the area.
Will the IR5000 tell me where the gas leak is along its path of detection?
No. The IR5000 lets you know that there is a leak somewhere between the IR5000 source and receiver. Only point detectors such as the IR2100 or S4000C will tell you more information as to the leak location.
What happens when someone stands in front of the IR5000 beam?
The unit will go into the beam block mode after the time delay has timed out and the output will go to 1.5mA. The display on the receiver will display F5.
Can I use the same unit to detect a methane gas leak and a propane gas leak?
No. Because of the bond structure of the heavy gases you must use a IR5000 which is programmed different than the unit for methane.
What happens when the front lenses of the IR5000 become dirty?
The IR5000 will go into a beam block mode, the output will go to 1.5mA and the display will show F5.
How do you calibrate the IR5000?
The IR5000 is calibrated at the factory. The unit can be re-zeroed but cannot be spanned in the field. We use a set of films to check the operation of the unit, but not to calibrate it. This is typical of all open path gas detectors.
What will the IR5000 read when it sees a gas cloud 25 meters wide with 100 ppm gas?
The display will show 2500 ppm•meters (100 ppm x 25 meters) and the ppm 4-20mA output will be at 12mA. The LEL 4-20mA output will only read 4.02mA.
What will the IR5000 read when it sees a gas cloud 10 meters wide with 25% LEL?
The display will show 2.5 LEL•meters (.25 LEL x 10 meters) and the LEL 4-20mA output will be at 12mA.
H2S FAQs
What is the recommended installation procedure for an H2S sensor?
The sensor should be located 12 to 36 inches from the floor wherever H2S gas may be present.
Why do we recommend mounting the sensor low?
H2S gas is heaver than air, thus it will settle.
What is the maximum distance the sensor can be located from the S4000T electronics?
Up to 3,700 feet.
Is the S4000T a 2-wire loop powered H2S detector?
No. The S4000T is a 3-wire transmitter that requires a 24 VDC, a ground and the 4-20mA signal out to the controller device.
What ranges are available for H2S detection?
The 3 ranges we have are: 0-20 ppm, 0-50 ppm and 0-100 ppm. The most common is the 0-100 ppm.
What H2S gas do we use to calibrate the S4000T?
We use 50% of the span. A 0-100 ppm detector requires 50 ppm H2S gas.
How do we calibrate an S4000T H2S detector?
We can use ampoules and a breaker bottle or a calibration kit consisting of a bottle of H2S gas, a .2 Liter/min regulator, 4 feet of tubing and a calibration cup.
Why would I use a calibration kit over ampoules?
The calibration kit allows for flowing H2S gas. This eliminates calibration errors from high humidity or from contaminants which absorb H2S. Flowing H2S is less likely to be absorbed by the moisture/contaminants.
When is a splashguard recommended?
All the time for outside installations and even inside installations where wash downs take place.
Flame Detection FAQs
Why would I use the FL3101 UV only flame detector over the FL3100 UV/IR?
The FL3101 responds in less than 500 milliseconds, thus it is ideal for fires that need fast detection. An example would be in a munitions plant.
Why would I use a FL3100 UV/IR flame detector over the FL3101 UV detector?
The FL3100 is immune to lightning and arc welding. Many compressor stations and other applications are located in areas where lightning is present.
Why would I use the FL3102 DFIR flame detector over the FL3100 UV/IR detector?
The FL3102 DFIR has the ability to see a fire through heavy black smoke. The FL3100 may not see the fire since the black smoke would block the UV side.
Why do I need to use the test lamp TL103 on the flame detectors if they already have self checking every minute?
The “COPM” self checking only tests the test lamps, windows for dirt and the UV and IR detector circuits. It does not test the relays or the 0-20mA stepped output. The TL103 allows you to test everything including the relays and output from the 0-20mA.
What is the advantage of a stepped 0-20mA output?
The 0-20mA signal to PLC’s and DCS systems can be used for warn and alarm conditions along with diagnostics. Should the detector be reading 8mA then there is some type of IR pulsating source present which then allows relocation or adjusting the sensitivity of the unit to overcome this background IR flickering source. This is also true if the output is at 12mA, which indicates UV only. The UV could be coming from arc welding or lightning.
How should the Flame Detectors be mounted?
We use 2 types of swivel mounting brackets. We recommend the detectors be mounted looking down at an angle to prevent dirt, dust and moisture from collecting on the windows.
Will the FL3100 series flame detectors detect a smoldering fire such as a cotton or cloth fire without a flame?
No, the GMI flame detectors will not detect this type of fire. A photoelectric or ionization smoke detect is best suited for this type of application.
Copyright © 2004 General Monitors, Inc. All logos, brand and product names are registered trademarks of their perspective owners. All rights reserved. Questions or comments to etech@generalmonitors.com.
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General Monitors, Inc. 26776 Simpatica Circle Lake Forest, CA 92630 Phone: 949-581-4464 Toll Free: 1-866-686-0741 Fax: 949-581-1151 etech@generalmonitors.com Product Manager: Ardem Antabian Additional contacts |
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Quick Reference |
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Home Product Spotlight Application Notes Technical Toolbox FAQs Articles Literature Press Releases Rep Quick Find Useful Links |
|||
Contact Information |
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General Monitors, Inc. 26776 Simpatica Circle Lake Forest, CA 92630 Phone: 949-581-4464 Toll Free: 1-866-686-0741 Fax: 949-581-1151 etech@generalmonitors.com Product Manager: Ardem Antabian Additional contacts |
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Feedback |
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Email your comments and suggestions here. |
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