GasGuard CO - Calibration Technologies
Contents
1. UARD Carbon Monoxide Sensor h GASGUARD CO CARBON MONOXIDE SENSOR SES coo c e co GasGuard CO Operating and Instruction Manual Table of Contents General description 4 T at 4 Locating the sensor 4 Installation guidelines 5 MV III PP 6 OD 21 14 eec 7 SAN UD 7 elle 7 2 2 9 10 ta 11 Calibration Technologies 866 394 5861 GasGuard CO Operating and Installation Manual General Description The GasGuard CO sensor is a 24 VDC three wire 4 20 mA sensor for carbon monoxide which utilizes proven electrochemical sensor technology for fast and accurate detection The standard detection range of the GasGuard CO provides real time continuous monitoring of carbon monoxide concentrations accurately down to 10 ppm without false alarms The upper detection limit is 200 ppm The GasGuard CO provides an industry standard linear 4 20 mA output signal compatible with most gas detection systems and PLCs The output signal is not affected by drastic temperature and moisture variations or by other atmospheric variations The transmitter2. circuit board is sealed in potting compound protecting sensitive electronic components and copper tracing from corrosion The specially vented chemical resistant polycarbonate enclosure protects the sensor from accidental damage weather and direct hose hits from clean up crews Installation Locating the sensor One of the most important considerations when installing GasGuard CO sensors is that they must be easily accessible for calibration and maintenance Always install the sensor in the breathing zone approximately 5 off of the floor This mounting location will provide the best personnel protection As a general rule of thumb install sensors no further than 30 from carbon monoxide sources Caution Remove protective cap The sensor is shipped with a cap installed over the electrochemical cell to preserve cell life The cell will not detect carbon monoxide gas with this cap installed Remove cap and discard during installation GasGuard Operating and Instruction Manual Installation Guidelines Remove and discard protective cell cap Always mount the sensor vertically Must be easily accessible for calibration and maintenance Mount the sensor close to the potential leak source 6 5 For optimum personnel protection mount sensor in 2 0 breathing zone 4 6 off of floor Take air movement and ventilation patterns into account To prevent electrical interference keep sensor and wire runs
3. away from mercury vapor lights variable speed drives and radio repeaters CO Protect sensor from physical damage forklifts etc eee If mounting sensor outdoors consider prevailing wind direction and proximity to the most likely source of leaks Protect the sensor from sun and 7 5 G 6 8 rain as much as possible Never mount the sensor in CA controlled atmosphere rooms because normal atmospheric levels of oxygen are required for operation For highly critical locations more than one sensor should be installed in each room m Mount sensor enclosures through the mounting holes as shown in Figure 1 Use the supplied self tapping screws for mounting on sheet metal surfaces Figure 1 Mounting dimensions GasGuard Operating and Installation Manual Wiring Electrical wiring must comply with all applicable codes Electrical Power 24 VDC regulated 350 mA Output Linear 4 20 mA output Monitoring equipment may have a maximum input impedance of 700 ohms Cable Recommendation 20 3 shielded cable General Cable C2525A or equivalent Length of cable to sensor should be no greater than 1 500 feet Monitoring Monitoring equipment must be configured to indicate a fault if the signal is below 1 mA All signals over 20 mA must be considered high gas concentrations Alarm setpoints should not be lower than 10 of full scale range Wiring Guidelines e Always use three conductor i
4. e depleted including e a period of time e exposure to high temperatures e continuous long term exposure to carbon monoxide When the cell becomes depleted the unit will give no indication of failure other than that the sensor will not respond For this reason it is absolutely essential that these sensors be calibrated on a regular basis Typical cell life in most applications is 5 years When the cell becomes depleted a replacement cell can be obtained from Calibration Technologies Simply unplug the cell s ribbon cable from the transmitter pull the old cell from the spring clip discard the old cell and replace it with a new one The sensor can be calibrated after a 12 hour warm up period GasGuard CO Operating and Installation Manual Specifications Detection Principle Electrochemical Detection Method Diffusion Gases Carbon Monoxide CO Range 0 200 ppm Custom ranges available Call for more information Output Signal Linear 4 20 mA max input impedance 700 Ohms Power Supply 24 VDC 350 mA Response Time less than 30 seconds less than 60 seconds Accuracy 5 of value but dependant on calibration gas accuracy and time since last calibration Zero Drift Less than 0 1 of full scale per month non cumulative Span Drift Application dependant but generally less than 2 per month Linearity 0 5 of full scale Repeatability 1 of full scale Wiring Connections 3 cond
5. ect output during span adjustment GasGuard Operating and Installation Manual P Sensor cable plugs into socket Inc 868 394 5861 Green LED indicates power GasGuanbp Red LED indicates filter activation Span adjustment Zero adjustment 40 to 200 mVDC mVDC Figure 3 Sensor board components and zero span adjustments Maintenance The GasGuard CO was designed for long life and minimal maintenance For proper operation it is essential that the test and calibration schedule be adhered to Calibration Technologies recommends the following maintenance schedule Maintenance Guidelines e The sensor is shipped with a factory calibration Sensor should be calibrated 6 months from purchase date e Calibrate the detector at least once every 6 months e Calibration should be performed with certified calibration gas Calibration kits and replacement cylinders are available from Calibration Technologies e n highly critical areas a response test should be performed between calibrations to verify proper sensor response and alarm functions This can be done with calibration gas The response test is not required if multiple electrochemical sensors are installed in the same room e All tests and calibrations must be logged GasGuard CO Operating and Instruction Manual Sensor Life These electrochemical cells are extremely reliable but several things can cause the cell chemicals to becom
6. nd should require only minimal adjustments after installation There are two pots on the preamp that are used for calibration Note Never measure sensor output in mA Always use mVDC or VDC voltmeter settings GasGuard CO Operating and Instruction Manual Zero Calibration After the unit is installed and has been powered up for a minimum of 24 hours the unit can be zero calibrated by the following e Be sure the unit is in clean air If unsure apply Zero Air gas at 0 5 to 1 0 L min e Adjust the zero pot until the sensor outputs 40 mV from Test to Test see Figure 3 Span Calibration The unit is factory calibrated and normally does not need to be spanned upon initial installation If span adjustment is required the following procedure will span the unit e Perform zero adjustment before spanning e Apply span gas at 0 8 L min span gas must be in air not nitrogen or other carrier e Sensor should react to gas within 10 seconds e Once the output signal has peaked or two minutes maximum adjust the span pot until the correct output is achieved see Figure 3 Note Below are a few response characteristics which may be an indication that the gas sensor is at or near the end of its useful life If any of these are observed the cell should be replaced e Slow response to recovery from calibration gas e Failure of the output to reach 50 of the calibration gas value prior to span adjustment e Unable to achieve corr
7. nsulated stranded shielded copper cable e Do not pull sensor wiring with AC power cables This can cause electrical interference e f cable runs cannot be made without a splice all splice connections should be soldered e Ground the shield at the main control panel Connect the shield wire in the sensor terminal block labeled SHLD e Use only the existing conduit hole for connections to the sensor J GasGuaARD CO 40 0 200 mVDC Test Figure 2 Wiring diagram lt Start up Before applying power make a final check of all wiring for continuity shorts grounds etc It is usually best to disconnect external alarms and other equipment from the sensor until the initial start up procedures are completed After power up allow at least 12 hours for the system to stabilize before testing the sensors Because sensors are normally located at a distance from the main unit the test time required and accuracy of the response checks will be improved if two people perform the start up procedures and use radio contact Start Up Test 1 One person exposes each sensor to carbon monoxide test gas 2 The second person stays at the control unit to determine that each sensor when exposed to the gas is connected to the proper input and responds causing appropriate alarm functions Calibration The GasGuard CO Sensor comes factory calibrated a
8. r than an authorized dealer or contractor or the installation of unapproved parts on the product The obligations set forth in this warranty are conditional on a proper storage installation calibration use maintenance and compliance with the product manual instructions and any other applicable recommendations of CTI b the buyer promptly notifying CTI of any defect and if required promptly making the product available for correction No goods shall be returned to CTI until receipt by the buyer of shipping instructions from CTI and the right of CTI to require that the buyer provide proof of purchase such as the original invoice bill of sale or packing slip to establish that the product is within the warranty period THE BUYER AGREES THAT THIS WARRANTY IS THE BUYER S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE CTI SHALL NOT BE LIABLE FOR ANY SPECIAL INDIRECT INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES INCLUDING LOSS OF DATA WHETHER ARISING FROM BREACH OF WARRANTY OR BASED ON CONTRACT TORT OR RELIANCE OR ANY OTHER THEORY 11 02 2013 SPECIALISTS IN Gas DETECTION I trib I2UJ 23 gt J Cc L c c c
9. uctor shielded stranded 20 AWG cable General Cable C2525A or equivalent up to 1500 ft Enclosure Injection molded NEMA 4X polycarbonate enclosure Captive screw in lid For non classified areas CSA approved 10 Temperature Range 20 F to 120 F 29 C to 49 C Humidity Range 5 to 100 condensing Dimensions 7 5 high x 6 5 wide x 3 75 deep Weight 2 lbs Limited Warranty amp Limitation of Liability Calibration Technologies Inc CTI warrants this product to be free from defects in material and workmanship under normal use and service for a period of one year gas sensor covered for six months beginning on the date of shipment to the buyer This warranty extends only to the sale of new and unused products to the original buyer CTI s warranty obligation is limited at option to refund of the purchase price repair or replacement of a defective product that is returned to a CTI authorized service center within the warranty period In no event shall CTI s liability hereunder exceed the purchase price actually paid by the buyer for the Product This warranty does not include a routine replacement of parts due to the normal wear and tear of the product arising from use b any product which CTI s opinion has been misused altered neglected or damaged by accident or abnormal conditions of operation handling or use any damage or defects attributable to repair of the product by any person othe
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