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Gas Data GFM 436 Technical User's Manual

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GFM 436
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Summary of Contents for Gas Data GFM 436

  • Page 1 GFM 436...
  • Page 2 1.1 Document revision history ....................... 5 2.1 Introduction ............................6 Features ..............................6 2.2 Spares list ............................7 3.1 Important safety related points ....................... 9 4.1 Introduction to the GFM436 Functions and Features..............10 4.2 GFM436 Instrument Specification ....................12 4.3 Specialist Functionality ........................
  • Page 3 8.2 Taking a Static Pressure (SP) Measurement .................. 30 9.1 Gas velocity Measurement with optional vane anemometer ............32 10.1 Gas Temperature Measurement with optional temperature probe ........... 34 10.2 DIP Meter Reading ........................35 11.1 Gas Temperature Measurement with optional temperature probe ........... 36 12.1 Sample Point Setup ........................
  • Page 4 Different types of gas ........................... 65 Important notes ........................... 65 Response Time ............................. 66 Technical data – MiniAir 6 Micro ......................66 Cleaning and maintenance ........................66 General handling tips ........................... 67 Cleaning instructions ..........................67 Conditions and exclusions ........................70 Disposal ..............................
  • Page 5 Issue: A Revision: 2 Date: 24/11/2022 ISSUE DATE REVISION DESCRIPTION 19/12/2013 Initial Release 28/11/2022 Brand Update...
  • Page 6 The Gas Data GFM436 handheld series of analysers is designed specifically for monitoring and analysing gas content of landfill, biogas and contaminated land sites. It measures the methane, oxygen and carbon dioxide content of site gases, gas pressure or vacuum, and gas velocity.
  • Page 7 GD order code Category Description GFM External Filters 25mm 18810 Filter GFM Internal Filters 15mm 18811 GFM External Filters 50mm 18818 GFM/Click! Sample Pipe Connector (Male Metal) 18812 GFM Sample Pipe Connectors (Female) 18813 Connector GFM/Click! Sample Pipe Connector (Male plastic) 18934 Calibration Check Gas - On Demand Flow Regulator C10 - Stainless Steel 18496...
  • Page 8 The Gas Data GFM has been designed to operate in typical field environments where flammable gases may be present. All ‘Special Conditions for Safe Use’ as detailed on the ATEX certificate (see Appendix F) must be adhered to. The following points must be observed:- •...
  • Page 9 • Only charge the batteries in a safe well-ventilated area using the charger supplied. • Ensure correct filter is used on the Gas In port – If any doubt please contact Gas Data • Use only Gas Data spares and accessories – See spares list.
  • Page 10 The Gas Data GFM436 is an ATEX accredited hand-held gas analyser designed specifically for monitoring and analysing soil gas parameters in greenfield and brownfield (contaminated land) sites and landfill sites. is lightweight, small and robustly manufactured in a weather resistant case making it suitable for use even in challenging field applications.
  • Page 11 Data is stored in non-volatile FLASH memory with a capacity of approximately 3000 data sets including the time and date it was stored and a 32-character alphanumeric label. Using Gas Data's SiteMan5 program data and labels can be transferred to and from a PC via a USB connection cable.
  • Page 12 General Ex. Rating to: II 2 G Ex ib IIB T1 Gb Ambient Temp Range -10 to 40 °C Battery Life 8 hours typical Battery Charge Time 2 to 4 hours Aspiration Rate 300 ml/min typical Storage Capacity >3000 Readings Protection Rating IP65 Dimensions...
  • Page 13 The instrument calculates and displays the Lower Explosive Limit (LEL) of Methane. This function is intended for use where methane has become mixed with air i.e. where oxygen is still present in normal atmospheric proportions with respect to atmospheric nitrogen. This is the worst case so if the gas sample is taken from a location where the oxygen content is depleted e.g.
  • Page 14 are “in scale” by referencing the original readings taken. No more waiting for samples to come back from the lab! Boreholes across a site can be compared and peak readings established to indicate those of significant interest, worst case and negligible etc. The PID (Photo Ionisation Detector) is the instrument widely accepted by the industry to quantify other hydrocarbon gases present in ground boreholes.
  • Page 15 This characteristic varies between PID manufacturers. For example, typically only 5 – 6% of methane will diminish the PID response of a RAE Systems unit to only one tenth of the correct value thus needing a PID compensation factor of 10. Instrument characteristics when subjected to high levels of methane do differ considerably (see chart of typical responses below).
  • Page 16 The GFM436 series instruments are supplied in a fitted case containing the following items: Allen GFM4XX instrument seseriesnstrinstrument Temperature probe (optional) Vane anemometer (optional) Spares kit Gas pipe Battery charger...
  • Page 17 Vane anemometer – Air velocity measuring Brass Temperature Probe – Gas line device. Instructions and information can be temperature measuring device. Instructions found on Chapter 8.0 – Gas Velocity and information can be found on Chapter Readings 9.0 – Gas Temperature Readings. In Car charger –...
  • Page 18 When turned on the instrument will take a few seconds to boot up. During this time a “loading” banner will be displayed. After booting up the instrument commences a warmup period. This is to allow all the sensors to initialise. During this period the letters “WRM” appear in the top right-hand corner of the display as shown.
  • Page 19 The screen also shows the instrument type (GFM436), its recalibration date and the serial number. If you ever need to contact Gas Data for assistance with your instrument, please quote the serial number. The Left Soft Key is labelled “Light” and will switch the Backlight on and off.
  • Page 22 6.4.1 To take a gas sample first connect the plastic sample pipe fitted with the filter to the 'Gas In' port at the top of the instrument. To do this, push the metal latch down then insert the connector at the end of the sample pipe. The port will lock the pipe in place and prevent it from being pulled out accidentally;...
  • Page 23 The Right Soft Key will toggle the pump on and off and will display “Start Pump” or the elapsed pump run time. When the elapsed time is displayed, pressing the soft key beneath will stop the pump. When the pump is running the screen will display live readings being taken from the gas. When the readings have stabilised press the Right Soft Key again to freeze the reading.
  • Page 24 The instrument will now be displaying the readings from the gas sample that has just been taken. This screen is the main display for viewing gas readings. In a standard configuration instrument, it shows CH4, CO2, O2, LEL, H2S, CO, C6H14 (Hex) and PID Cf. Four readings are shown on screen at a time and pressing the Up and Down Keys will scroll up and down to view the other values The right arrow key will navigate to Gas Display 2.
  • Page 25 The second gas display show more analysis results from the gas being sampled. It is accessed by pressing the Right Arrow key. This display shows CH4, LEL, C6H14 (Hex) and PID Cf all on the same screen at the same time. The Right Soft Key will toggle the pump on and off and will display “Start Pump”...
  • Page 26 When finished turn off the gas tap and remove the gas pipe. Take great care when connecting the pipe to the gas tap to avoid gas leakage.
  • Page 28 The GFM436 will measure Flow, Peak Flow, DP and AP at the same time. This requires a connection to be made to the Flow in port as shown in the diagram above. The Flow Sample pipe is the section of pipe without the filter. This can be separated from the Gas Sample pipe at the quick release coupling.
  • Page 30 Four readings are shown on screen and pressing the Up and Down Keys will scroll up and down to view the readings. Scroll down to use the SP (Static Pressure) function. Press the right soft key to begin sampling. Zero the readings by pressing the Middle Soft Key (Zero). Press the right soft key to stop sampling.
  • Page 31 ______________________________________________________________________ It is important to complete the zeroing in an environment where there is no flow or pressure and ensure that the end of the flow tube is not exposed to any external flows or pressures. ______________________________________________________________________ Connect the open end of the gas flow tube to the gas tap or sample point on the pipework to be checked.
  • Page 32 Connect the vane anemometer to the Comms port at the top of the instrument. Locate a suitable gland or bung on the pipework and insert the anemometer. When the anemometer is as far into the gland as possible without opening the tap, open the gas tap. Finally, push the anemometer into the gland far enough to ensure that the impeller is in the centre of...
  • Page 33 When the reading has stabilised, press the “Sample” key to retain the reading. The anemometer can now be removed from the pipe. Take great care when inserting the anemometer to avoid gas leakage. Take great care when removing the anemometer. In particular, avoid standing with your face in direct line with the gland because gas can be expelled at great force.
  • Page 34 Connect the temperature probe to the Comms port at the top of the instrument. Locate a suitable gland or bung on the pipework and insert the temperature probe. When the probe is as far into the gland as possible without opening the tap, open the gas tap. Finally, push the probe into the gland far enough to ensure that the tip is in the centre of the gas pipe.
  • Page 35 The DIP Level function on the GFM436 allows two DIP level readings - DIP1 and DIP2 - to be entered and stored for each location ID. To change the DIP Level, select the field and press OK. Then use the Left and Right Key to highlight the digit to be changed and use the Up and Down Keys to increment or decrement that number.
  • Page 36 The Menu Window is used to configure the data storage functionality of the instrument. It contains options for setting up sample points, unattended data logging parameters, viewing stored readings and setting the clock. The Up and Down Keys will scroll up and down and pressing the OK Key will take you to the highlighted option.
  • Page 37 The Sample Point Setup is a screen for creating and deleting sample points. A sample point can have up to three labels (IDs) each of which can be up to eight characters long allowing for a three-layer labelling system for sample points. For example, ID1 could be the project or customer, ID2 could be the site and ID3 could be the borehole name or number.
  • Page 38 Diagrammatic explanation of the relationship between the three levels of hierarchical storage available.
  • Page 40 The GFM436 has a built-in "Unattended Data Logging" facility. This allows the instrument to be programmed to carry out repeated samples over a defined time period. This functionality is common with the GFM426 instrument. Further details can be found in Appendix C. The View Readings Display is a display for viewing and deleting previously stored readings.
  • Page 43 The Clock Display allows the user to view and edit the date and time. The Left and Right Keys change which field is selected and the Up and Down Keys increment or decrement that field. Pressing the OK Key or the Left Soft Key, labelled “OK”, will save the changes and exit the Clock Display.
  • Page 44 The Store Menu allows you to select a sample point and either store a single sample to it or begin a log at that sample point using the logging parameters chosen in Logging Setup. Use the Up and Down Key to highlight the ID you wish change then press the OK Key to select it. With an ID selected use the Left and Right Keys to change to the sample point you want then press OK.
  • Page 45 For details of the user calibration function, please see appendix B. Incorrect user calibration will produce eroneous results. To help prolong the time between charges, the GFM will automatically turn off after 15 minutes of inactivity. This does not occur whilst the instrument is connected to the mains supply.
  • Page 46 A series of horizontal bars of different lengths in the top right-hand corner of the display screen indicates the state of charge of the rechargeable batteries. 3 bars indicate a fully charged battery; 2 bars three- quarters charged; 1 bar half charged; no bars quarter charged or less – time to recharge. When all the bars except the shortest have disappeared, it is time to recharge the batteries or replace them with another battery pack.
  • Page 47 To change the batteries, remove the two screws on the rear of the instrument, then lift the battery cover and remove the battery pack from the recess. Place the new battery pack in the recess, making sure that the polarity is correct, replace the battery cover and secure with the two screws.
  • Page 48 There is a gas filter built into the input of the instrument. Check this filter weekly and change it when it becomes clogged or dirty. Always use the correct filter of the recommended type, which can be supplied by Gas Data Limited. If you use a non-recommended filter, this will invalidate the warranty on the instrument.
  • Page 49 Calibration of the GFM series of instruments involves the use of pressurised cylinders of test gases. A cylinder of the appropriate gas at the specified concentration needs to be connected to the “Gas In” port at the top of the instrument with the valve open when calibrating a point. It is recommended that a demand flow regulator is used.
  • Page 50 The use of pressurised cylinders of test gases may produce hazards including the following: Warning • High pressure gas leakage • Release of flammable gas mixtures • Release of toxic gas mixtures Always follow the safety guidelines given by your test gas cylinder supplier.
  • Page 51 Press the Right Soft Key, labelled “Calibrate” to go to the User Calibration Display. There is a choice of four calibration options for each user calibratable channel, use the Up and Down Keys to scroll between gasses and calibration options: 1.
  • Page 52 Connect the calibration gas to the 'Gas In' port. Flow the gas for 3 minutes to allow the reading to fully stabilise. Finally press the Middle Soft Key, labelled “Calibrate” to calibrate the channel. To calibrate the gas channel to the low range cal point scroll up or down until you reach the 'X.X% calibration' option for the desired gas channel (please see table above for low range cal points Page 45).
  • Page 53 Once calibration is complete, press the Left Soft Key, labelled “OK”, to return to the Banner Display.
  • Page 54 To access the Logging Setup Screen, press the Middle Soft Key ("Menu") from any of the measurement display screens Use the arrows to highlight "Logging Setup" and press the OK button. Logging Setup is a menu for setting up unattended data logging parameters. These parameters are: •...
  • Page 55 Pressing "OK" will scroll through these options. When you have selected the required value, use the "Up/Down" arrows to move to the next parameter. A selection of 3 minutes, for example, will allow the pump will run for 3 minutes and then the instrument will store the analysis values it measured at the end of the 3 minute period.
  • Page 56 With battery save enabled the instrument will switch itself off 5 seconds after taking a sample unless it is interrupted, for example by a Key being pressed or the log ending, then switch itself back on approximately 30 seconds before it is due to start taking its next sample. With battery save disabled the instrument will remain turned on at all times, until the battery is empty.
  • Page 57 The Logging Display shows the total number of samples to be taken in the log, “Total Logs”, and the number of samples which have been logged, “Logged”. When the pump is running and it is sampling a countdown timer and “Sampling” will be shown, when this reaches 0 the sample will be stored and a popup will appear saying “Reading stored”...
  • Page 58 A popup saying “WARNING Switching Off May Interrupt Sampling” will be shown when the instrument wakes itself as manually switching the instrument on or off during logging may interrupt sampling or cause a log to be missed or not taken.
  • Page 60 The following three charts are included to enable the operator to make quick and easy conversions from velocity measurements provided by the vane anemometer to flow rates. Velocity - Flow conversion chart 160.00 140.00 120.00 100.00 80.00 50mm 60.00 40.00 20.00 0.00 Velocity (ms...
  • Page 61 Velocity - Flow conversion chart 6000.00 5000.00 4000.00 50mm 100mm 150mm 3000.00 180mm 220mm 250mm 2000.00 1000.00 0.00 Velocity (ms The formula for calculating the conversion is: where = flow in m = pipe inside diameter in mm = velocity in ms...
  • Page 62 _________________________________________________________________________________________ The GFM400 Series is suitable for use in Zone 1 and 2. Different gases are grouped according to how easily they are ignited. Some examples are given below. (For other gases please contact Gas Data). Relative Ignition Group Hydrogen/Acetylene...
  • Page 63 The technique of intrinsically safe design and construction is defined in the European Standard EN50020:1995. The technique identifies potential sources of ignition (by spark or by heat) and specifies the design of safety circuits that limit the energy of the spark and/or the component temperatures such that they cannot ignite the gases expected within the hazardous area.
  • Page 64 Different gases will be ignited at different temperatures. Some examples are given below. MINIMUM Required T class Acetylene Hydrogen Ethylene Carbon monoxide Hydrogen sulphide Ammonia Propane Methane _________________________________________________________________________________________ The GFM400 Series is designed to meet the requirements of class T1. The GFM400 Series has been submitted for European Type Assessment.
  • Page 65 _________________________________________________________________________________________ Schiltknecht anemometers do not form part of the ATEX certification of the Gas Data GFM series. Contact Gas Data for further advice on the safe use of these probes These operating instructions are intended to ensure that the Schiltknecht measuring instrument and probe remain perfectly serviceable, guaranteeing fault-free and safe operation.
  • Page 66 Response Time of electronic: When connected to supply (on/off): immediate Time to reach 63 % of end value: 424 ms Response Time of Vanes: Increase of flow: 1.0 sec. Decrease of flow: 8.0 sec. Measuring range 0.7 – 40 m/s Accuracy +/- 1.0% fs Operating temp.
  • Page 67 • Protect the probes against severe vibration • Do not kink the connector cable (risk of cable break) • Never allow hard objects to contact rotating impellers. • Always carry out probe cleaning according to the cleaning instructions -Never immerse probes in solvent •...
  • Page 68 Cleaning agents which extract the plasticizer from the plastic are never to be used for plastic probes (practically all solvents!). We recommend the following for cleaning the probes: • running water • soapy water • pure benzene Cleaning example: 1) Carefully swish the top part of the impeller back and forth in clean, pure benzene for ca. 10 min. Then swish the top part of the impeller back and forth in clean kerosene for ca.
  • Page 69 • Window cleaning fluid (without ammonia) -and for any stubborn deposits, • Pure benzene These solutions are only to be applied to the parts with a fluff-free cloth. Only carry out surface cleaning. The parts are never to be immersed in the solution. Snap Head The snap head fixing system renders it very simple to fit a new impeller to the flow probe: this saves costly non-productive time and in the event of damage to the snap-head enables the operator to have the probe...
  • Page 70 This instrument is guaranteed, to the original end user purchaser, against defects in materials and workmanship for a period of one year from the date of shipment to the user. During this period, Gas Data Limited will repair or replace defective parts on an exchange basis. Freight charged to and from the Gas Data factory or authorised service centre will be paid by the end user.
  • Page 71 Unit 4, Fairfield Court Coventry, CV3 4LJ, United Kingdom Connect office@gasdata.co.uk +44 (0) 24 7630 3311 gas-data gasdata.co.uk...