EI-5
Ethane Identifier
User Manual
LIABILITY
Every care has been taken in the preparation of this document, but Hetek Solutions Inc. does not accept any responsibility for errors or omissions and their consequences. Information in this document is subject to change without notice. This document does not constitute a specification or basis for a contract. Your statutory rights under law are not affected.
AREAS OF USE
Exposure to certain chemicals can result in a loss of sensitivity of the separation column and semi-conductor sensor. Where such environments are known or suspected it is recommended that more frequent response checks are carried out.
Do not use instrument in potentially hazardous atmospheres containing greater than 21% Oxygen.
STORAGE, HANDLING AND TRANSIT
The instrument is designed to handle harsh environments. If not subject to misuse or malicious damage, the instrument will provide many years of reliable service. Under conditions of prolonged storage the batteries should be removed to prevent any leakage and damaging the instrument. The instrument should be stored in the original carrying case when not in use.
TABLE OF CONTENTS |
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INTRODUCTION...................................................................................... |
1 |
PRINCIPLE OF OPERATION ........................................................................ |
2 |
INSTRUMENT SPECIFICATIONS .............................................................. |
4 |
STANDARD KIT COMPONENTS................................................................... |
5 |
OPERATING INSTRUCTIONS ..................................................................... |
6 |
DATA LOGGING USE .................................................................................... |
8 |
INTERPRETING READINGS...................................................................... |
11 |
TYPICALELUTIONTIMES ......................................................................... |
12 |
MANUFACTURER’S RECOMMENDATIONS .......................................... |
13 |
CALIBRATION VALIDITY ........................................................................... |
14 |
MAINTENANCE INSTRUCTIONS ............................................................ |
15 |
TROUBLE SHOOTING .............................................................................. |
16 |
REPLACEMENT PARTS & ACCESSORIES ............................................. |
17 |
WARRANTIESAND WARRANTYREPAIR ............................................... |
18 |
CUSTOMER ASSISTANCE, MANUFACTURING AND SERVICE |
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LOCATIONS.................................................................................. |
19 |
INTRODUCTION
The Hetek Ethane Identifier, Model EI-5, is a portable, highly sensitive battery operated combustible gas analyzer designed specifically to detect the presence of Ethane in Natural Gas by elution (separation).
The Ethane Identifier is a supplementary instrument, used primarily when it is necessary to determine in the field, whether or not a particular combustible indication is the result of escaping utility natural gas or a conflict gas such as naturally occurring methane.
Occasionally, it becomes necessary for a gas utility to identify a combustible gas or vapor in the field, to determine whether it is the gas normally distributed by that utility, or perhaps a fermentation gas (marsh gas, landfill gas, soil gas) that is sometimes present in the ground or in sub-surface structures.
It has been found that a satisfactory “tracer” in natural gas distribution areas is Ethane. Ethane is usually present in significant concentrations in natural gas, but it is not present in the general run of conflict gases, such as fermentation gases, gasoline and solvents. In many areas, natural gas being distributed is de-ethanized to the level that the Ethane component is not detectable by old style hot-wire instruments. Ethane is being stripped out at the gas fields or scrubbing centres and diverted as a feedstock for the petrochemical industry. However, some residual Ethane still remains in natural gas and this Ethane is readily detectable by highly sensitive instruments such as the Hetek Ethane Identifier.
It must be understood that this instrument is not a quantitative instrument and does not replace a Combustible Gas Indicator (C.G.I.). Users should continue to use a Heath Detecto Pak Infrared (DPIR) or Combustible Gas Indicator to locate and measure leaks.
Features:
•Detects the presence or absence of ethane in less than 2 minutes
•Graphical color display
•Building data logging
•Wrapping memory
•One second logging rate, 64000 reads
•Carrier gas not required/ Built in pump
EI-5 Manual Rev A |
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PRINCIPLE OF OPERATION
When the presence of a combustible gas or vapor has been established with a C.G.I., use the Ethane Identifier with the internal pump to draw a sample into the instrument. The valve should be in the “Sample” position. No display indication will occur as the sample is being drawn into the instrument. As the sample is drawn into the instrument, a portion of the sample is trapped inside the instrument in the short sample loop. Switching the valve to “Time” position sends this trapped sample through the separation column where the various components in the sample are separated by their molecular size. The internal pump is used to push the sample through the instrument.
If more than one type of combustible component is present in the sample the lightest one (smallest molecule) will be released first followed by the next heavier (larger molecule).
These components pass over the sensor in the instrument and are observed visually on a display. If a record of the chromatographic analysis is required the data logger records the date and time and a value at one second intervals. Normally, a full-scale graphical peak will occur for each component but not always, particularly, when low concentrations are being analyzed. The instrument can provide reliable results with sample concentrations measured on a C.G.I. of 800 ppm to 100 LEL natural gas. However, for optimum results attempt to analyze samples in a concentration of about 10 LEL to 75 LEL. To again emphasize the design of the instrument, there is no indication on the display when the valve switch is in the “Sample” position. It is mandatory to use a C.G.I. to determine sample concentration before using the Ethane Identifier. Zeroing the meter exactly at “O” is not critical as the graph may drift during the test. This normally presents little problem to the end result.
Electronic Principle: The electrical schematic is based on the semi-con- ductor type sensor (metallic oxide bead). The Hetek Ethane Identifier uses a semi-conductor type sensor that is pre-determined to be ultra sensitive to the light hydrocarbons. The tough bead of metallic oxide, semi-con- ductor material, coats itself with oxygen molecules, which is considered
EI-5 Manual Rev A |
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the equilibrium condition in clean air. Any substance foreign to clean air disturbs this balance, changing the ion flow in the conductance band of the semi-conductor detects the low concentration and early presence of foreign gases (methane, ethane, propane) rather than giving a quantitative measure of their concentration. As the various components or hydrocarbons elute through the separation column they react on the semi-con- ductor and the resulting change in electrical resistance is amplified and presented visually on the instrument display.
Flow System: The flow system is so arranged that the Ethane Identifier cannot be used as a leak locator. It is set up as a field type gas chromatograph to differentiate between gases by means of a multi-port selector valve, short sample loop and separation column.
Valve “Sample” Position: With the selector valve set to “Sample” the sample is drawn into the instrument and fills the short sample loop. Excess sample passes through the sample system and exits through the port on the end of the instrument. The sample does not pass over the sensor in this position so no meter readings occur.
Valve “Time” Position: After a gas sample has been drawn into the instrument, the combustible gas is present in the short sample loop. Switching the valve to the “Time” position causes the internal pump to push the sample through the separation column (Chromatograph), over the sensor, and then exhausts it to the outside of the instrument case at the vent port located at the bottom of the instrument.
EI-5 Manual Rev A |
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INSTRUMENT SPECIFICATIONS
Instrument Weight: |
1.3 lbs (0.59 kg) |
Carrying Case Weight: |
7.3 lbs (3.3 kg) Includes Hydrocarbon |
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Filter and accessories. |
Instrument Dimensions |
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(LxWxH): |
8.25 x 4.0 x 1.25 in (21 x 10 x 3 cm) |
Carry Case Dimensions |
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(LxWxH): |
17.5 x 13.5 x 4.5 in (45 x 34 x 12 cm) |
Sensitivity: |
16 PPM C2H6 In Air (Detects Ethane in |
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800 ppm sample of natural gas which con- |
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tains only 2% Ethane |
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by volume) |
EI-5 Manual Rev A |
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