Calibration Manual GD FH Tue IR and Buveco 12 1 E [PDF]

Zitiervorschau

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Calibration Instructions Gas Detection systems This instruction shows how to use the Calibration kit 5201013-00A for the range of ST200/400/600/700 range of detectors as well as Salwico GD FH Tue IR infrared detectors. The kit contains a regulator with fixed flow suitable for a range of detectors, a rubber hose and a Flow-cap with a coupling, for connection to the ST200/600/700 range of detectors. In addition, a suitable Gas bottle must be supplied with suitable gas-mixture for the detectors onboard. There are various types available, see separate list.

Pic 1. The kit, with a gas bottle

Doc.no: 6300792 Calibration manual Salwico GD FH Tue IR and Buveco 12 1 E

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Calibration of Salwico GD FH Tue IR Infrared 4-20 mA Gas detector The Salwico GD FH Tue IR detectors are normally calibrated simply by connecting the hose from the regulator to the calibration connection at the end of unit. Remove both covering caps if they are fitted. To avoid unwanted trips and alarms, go to the Central panel and disconnect outgoing alarm functions. At the detector, open the bottle regulator valve and start the gas- flow. At the control-panel, see the reading in % LEL. The Salwico GD FH Tue IR signal output can only be adjusted with the hand-held calibration tool. See separate instructions! Pic 2.

On a duct-mounted unit connect to the hose-connections as shown in Pic 3. Note! The airflow in the duct must be off during the calibration, or the air is likely to be diluted and calibration void with too low readings being displayed. In this picture, the connections box can be seen, but the detector is fitted inside the duct. Pic 3.

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Calibration of the ST200 / 600EX Hydrocarbon Catalytic Detector. The ST200 and ST600-EX detectors for 0-100% LEL Hydrocarbon can be calibrated and out-signal adjusted. Reading at 0% is 4,0 mA, and full range 100% LEL is 20mA. Tools required for this operation are: - A small terminal screw driver, with thin straight tip. - A Multi-meter with mA (Mili-ampere) capacity. Connect the Flow-cap to the sensor head as shown in Pic 5, and the measuring tips of the multi-meter to the test-points in the detector. Plus is red, minus is black. Picture shows a ST200, the ST600EX has identical connections and calibration, only fitted in an EX proof housing Pic 4.

Before gas Calibration is made, a Zero-adjustment should be made. Connect the mA meter to the two test-points as shown in Picture 5. Pic 5.

The display readout should be 4,0 mA with normal air / zero gas exposed to the sensor. Adjust to this reading with the “Zero” pot, marked in red where the screwdriver is held.

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Span calibration with testgas: Connect the suitable test-gas for the detector, normally a 50% LEL mixture. The ST200 and ST600EX can only respond to gas in normal Air. This means that Calibration gas in N2 / Nitrogen are not suited for these detectors. On LNG vessels a 50% LEL gas of CH4 Methane in air is to be used, for LPGs and Tankers we normally recommend a 50% LEL C3H8 Propane gas in air. Adjust the reading to 12,0 mA using the “SPAN” pot, see pic 6. Pic 6.

Catalytic detectors have a limited lifespan of up to 5 years, but can be “poisoned” by silicones, salt air and very humid air etc and their output will be reduced. When the readout of 12,0 mA cannot be reached even with the “SPAN” pot in the bottom position, the sensor cell must be replaced to a new one. Consilium Replacement article number for ST200and ST600EX detectors is 004460-S. When a new sensor is fitted, a new Zero adjustment as well as span calibration should be made. For the ST600-EX the procedure is identical as above, but note that the EX-Seal is void if the unit is open, so necessary precautions in the working area may be required. Check on site what is applicable before the unit is opened up. Pic 7.

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Gas detectors type ST600EX-IR & ST700IR. Remove the cover from the detector. The calibration push buttons is situated at the PCB below the display. In this type of detector no Multi-meter required, the mA signal is adjusted by pressing the keys.

SW4

•

SW3

SW2

•

•

Menu Enter

Up

SW1

• Down

Enter the USER password 122 to access the user menus. • Push SW4. The display shows PASS • Push once (SW3) and twice ( SW2) to insert the password. • Push again on PASS (SW4). • The display shows E1, the first calibration menu. To change menu number, press SW1 or SW2. E2 will be used later for Span calibration. Zero adjustment: • Apply Zero gas (or simply clean air, make sure there is no LEL content in the area before work starts) to the sensor. • Press SW3 (Enter) to activate the zero menu. • Press SW3 (Enter) to perform the ZERO calibration. Reading should now stabilize to zero. One can press SW3 several times and wait a little to make sure the reading is stabile, half a minute or so. • Press SW4 (Menu) – The display will return to its standard mode operation after displaying some numbers, the calibration factor.

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Span calibration: A ST600EX-IR detector with a gas bottle connected to the flow-cap. Pic 8.

• • • •

• • •

•

•

Enter the USER password in the detector. See above for Zero adjustment. Select the menu E2 for span calibration by pressing SW1 (Down). Press SW3 (Enter) to activate the menu. Use the SW2 (UP) and SW1 (DOWN) buttons to adjust the display reading according to the calibration gas concentration. 50% LEL is the standard gas in our gas bottles, if any other bottle is used the corresponding LEL concentration must be chosen in the display. Press SW3 (Enter) to confirm the calibration gas concentration setting. Now apply the calibration gas to the sensor by opening the regulator valve. Wait until the display value is stable. (The value does not correspond to the concentration most likely.) On newly fitted sensor the reading may very well be zero or very much higher than 50% LEL before the next step is done. Press SW3 (Enter) to confirm the SPAN calibration. Now the reading should go to 50% LEL. This can be done several times and it will take up to a minute or more for the reading to stabilize. Remove the calibration gas and wait until the gas has disappeared and reading is back. Press SW1 (Menu) – The display will, after displaying some figures corresponding to sensor factor curves, return to its standard mode operation again and the correct mA signal will be sent out. One can also press SW1 while gas is still flowing and reading is high, but the detector will then immediately after restart send out the high mA signal and the central go into alarm condition. This may or may not be a problem, depending on preparations before the calibration commenced.

Consilium Replacement Sensor only for ST600EX-IR and ST700-IR is 004483.

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H2S sensor 0-30 ppm ST400 4-20 mA. The H2S sensor is Electrochemical and measures H2S content by means of chemical reaction. H2S – Hydrogen Sulphide – is a sticky gas and smells very distinctly from rotten eggs.Its toxic and dangerous in also rather low concentrations. Normal measuring range is 0-30 ppm, our standard calibration bottle 5201005-00A contains 20 ppm of gas in air. For SW2020 a mix-bottle is often used, with H2S 20 ppm as well as N2 99% and C3H8 50% LEL, it’s the article 5201010-01A. Consilium Replacement article number

for ST400 H2S detectors is 004462-S. Zero adjustment: Connect the Multi-meter set to mA as shown in Pic 9, and adjust with the “ZERO”pott to 4,0 mA signal output. Pic 9

Span calibration: Note! The ST400 for H2S is available in two types. Type 1: 0-25 PPM. mA-signal at 20 ppm = 16,8 mA. Type 2: 0-30 PPM. mA-signal at 20 ppm = 14,6 mA. To verify which type is in use, make a span calibration as below and verify the display reading in the central cabinet. If the readout at 14,6 mA is less than 20 ppm a calibration with 16,8 mA set-point must be done. Connect the gas-bottle with flow-cap to the sensor head, and open the regulator valve. When the reading is stabilized, adjust the readout to 14,6 mA (or 16,8 mA) with the “SPAN” pot. If this reading cannot be reached, the sensor-head should be replaced. Note that due the sticky nature of the H2S as short hoses as possible is to be used, and response can be estimated to several minutes in some cases.

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O2 Sensor ST400 0-25% VOL The O2 sensor is Electrochemical and measures O2 content by means of chemical reaction. The lifespan of the sensor is about 1 year, and it has a short shelf-life – stocking it onboard is not advised and this will reduce the operational lifetime.

Consilium Replacement article for sensor only of ST400 O2 detector is 004472. Calibration of normal O2 level: Connect the Multimeter to the testpoints. The O2 is calibrated with fresh breathing air, and is normally 20,8%. Test-points for the meter as well as “Zero” and “Span” pots indicated below. Do not adjust the other pots. Pic 10

Connect a mA meter to the test-terminals and adjust the readout on the “SPAN” pot to 17,4 mA when normal breathing air is present. In a SW2020 flow-system, make sure the flow is stabile at about 40 ln/h during this operation.

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Pic 11.

For Zero adjustment a Nitrogen-mix should be used, with a pure N2/Nitrogen concentration. A gas-bottle with Hydrocarbons in N2 can also be used, as long as the O2 content is zero percent. We recommend the Consilium Article 5201006-00A with 100% N2. Connect the gas Bottle and open the regulator valve. Wait for the mA signal to drop and stabilize, then adjust the reading to 4,0 mA. Pic 12.

Typical signs for when lifespan of the O2 sensor is up is drifting values, instable readings and un-ability to set the 17,4 mA signal even with the SPAN pot in max position. A new sensor is supplied without the metal housing and must be fitted in the housing like below. This applies to both H2S and O2 sensors of ST400 type.

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Pic 13.

This calibration instruction is intended for the range of calibration bottles in use from 2011 from our supplier STG. If older equipment is used the procedure still applies, and set-points of mA signals etc are identical in the most cases. For calibration support etc, contact your local Consilium office, or forward your requests to: [email protected] For spare part orders and calibration bottle orders, contact your local Consilium office, or: [email protected]

Consilium Marine and Safety, A/S Dept. Gothenburg, Sweden. +46 31 710700