LI-COR LI-7820 Instruction Manual Download | Manualshive

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Accessory kit

Part Number
9978-195

The accessory kit includes some accessories and replacement components that may
be useful to you. Additional replacement parts are available from LI-COR or your
local distributor.

Description

Quantity

Part Number

Replacement dry-down chemical pack (17 grams each)

3

622-17627

Stainless Steel Screws ; M3×0.5; 8 mm

6

150-14419

O-ring; 27×1.5 mm

2

192-16956

O-ring; 22×2.5 mm

4

192-17345

Stainless Steel 1/4" Ferrule and Nut Set

5

300-15025

Filter support disks

2

9878-280

Filter pack; 2-micron (10 filters)

1

9978-234

Optional accessories

In addition to the items already mentioned, the analyzer may include the following
accessories.

Auxiliary power cable

Part Number
9968-242

This optional component allows you to power the instrument from an external DC
power supply, such as a deep cycle battery. It has a connector for the instrument
power connection and bare leads for a power source. Power requirements are given
in

External power source

Backpack kit

Part Number
6578-380

The backpack kit is an optional accessory that can be used to carry the instrument.
It features a padded back and padded shoulder straps with a padded waist strap and
chest strap to help support the instrument as you carry it.

Section 1. Introduction to the LI-7820

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Accessory kit

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Summary of Contents for LI-7820

Page 1: ...LI 7820 N2O H2O Trace Gas Analyzer Instruction Manual ...

Page 2: ......

Page 3: ...and Canada envsales licor com Regional Offices LI COR Biosciences GmbH Siemensstraße 25A 61352 Bad Homburg Germany Phone 49 0 6172 17 17 771 envsales gmbh licor com LI COR Biosciences UK Ltd St John s Innovation Centre Cowley Road Cambridge CB4 0WS United Kingdom Phone 44 0 1223 422102 envsales UK licor com LI COR Distributor Network www licor com env distributors ...

Page 4: ...U S and other countries Printing History Copyright 2020 LI COR Inc All rights reserved Publication Number 984 19432 Created on Wednesday March 17 2021 Notes on Safety This LI COR product has been designed to be safe when operated in the manner described in this manual The safety of this product cannot be assured if the product is used in any other way than is specified in this manual The product i...

Page 5: ...quired to correct the interference Waste Electronic and Electrical Equipment WEEE Notice This symbol indicates that the product is to be collected separately from unsorted municipal waste The fol lowing applies to users in European countries This product is designated for separate collection at an appropriate collection point Do not dispose of as household waste For more information contact your l...

Page 6: ...n goes to press As a result small inconsistencies between the documentation and the instrument may be present Updates to this document as well as application notes technical literature videos that support the product and software updates will be available from licor com env support search for LI 7820 We appreciate feedback on this manual Send your comments to envfeedback licor com For technical su...

Page 7: ...versal power adapter 2 2 Rechargeable batteries 2 2 External power source 2 3 Connecting with the instrument 2 4 Connecting over wireless 2 5 Connecting over a wired network 2 6 Enabling and disabling Wi Fi 2 7 Instrument display 2 8 Status codes 2 9 Powering off the instrument 2 10 Storing the instrument 2 11 Shipping the instrument 2 11 Section 3 Applications of the LI 7820 Flow schematic 3 1 So...

Page 8: ... Export 4 15 Section 5 Troubleshooting Connection problems 5 1 Request to connect to instrument network rejected by Android OS 5 1 Unable to connect with the instrument over a wired connection 5 1 Unable to connect with the instrument over a wireless connection 5 3 Measurement problems 5 4 Readings drift or step change unexpectedly 5 4 Pressure readings are questionable or unstable 5 4 Gas density...

Page 9: ... into the interface 7 3 Setting the zero calibration 7 4 Setting the span calibration 7 5 Rebooting the instrument 7 6 Powering off the instrument 7 6 Basic commands with a Python script 7 7 Configuring paho mqtt in Windows 7 7 Configuring paho mqtt in Mac or Linux 7 7 Streaming data into the Terminal Program 7 8 Downloading data in a date and time range 7 9 Additional commands 7 10 Appendix A Mea...

Page 10: ...viii ...

Page 11: ...nd stores in its internal memory N2O dry mole fractions in air corrected for both the spectroscopic interferences and dilution due to H2O See Measurement overview on page A 1 for a brief summary of OF CEAS What s what If you have just taken delivery of the instrument check your packing list to be sure you received everything that you ordered The LI 7820 includes some or all of the following compon...

Page 12: ...he optional DC power cable part num ber 9968 242 See Power options on page 2 2 Warning Use the safety approved power cord supplied with the instrument The instru ment power supply is equipped with a 3 wire grounding plug This plug will only fit into a grounded outlet Do not defeat the purpose of the grounding type plug Do not place the instrument where the power cord will be walked on or exposed t...

Page 13: ...er Warning Lithium ion batteries may cause environmental damage or damage to human health if they are disposed of improperly Do not dispose of the batteries in unsorted municipal waste or an incinerator Many localities have battery recycling facilities that will accept lithium ion batteries Check your local regulations to determine how to safely dispose of the batteries Advertissment Les batteries...

Page 14: ...a grounded outlet Do not defeat the purpose of the grounding type plug Do not place the instrument where the power cord will be walked on or exposed to water or chem ical spills Avertissement Utilisez le cordon d alimentation approuvé pour la sécurité fourni avec l instrument L alimentation de l instrument est équipée d une fiche de terre à 3 fils Cette fiche ne rentrera que dans une prise de terr...

Page 15: ...onal accessories In addition to the items already mentioned the analyzer may include the following accessories Auxiliary power cable Part Number 9968 242 This optional component allows you to power the instrument from an external DC power supply such as a deep cycle battery It has a connector for the instrument power connection and bare leads for a power source Power requirements are given in Exte...

Page 16: ... with the backpack kit l Close the clasps and tighten the straps so that the instrument is secure l Do not block the vents or set the instrument in standing water l If you are unable to lift the backpack kit comfortably or tighten the straps con sider enlisting the help of a strapping assistant l Clip the chest and waist straps Tighten all of the straps snugly 1 6 LI 7820 N O H O Gas Analyzer ...

Page 17: ...rsal power adapter When powered by batteries only you must press the power button to turn on the instrument Upon powering on the instrument will issue a series of status codes as it completes the start up cycle The pump will start running when the optical bench approaches 55 C If starting from room temperature it will take about 20 minutes before you can connect and another 10 or 15 minutes before...

Page 18: ...quired to power the instrument The instrument supports hot swapping meaning that you can remove a partially depleted battery and replace it with a charged one and measurements will not be disrupted as long as the instrument is powered by a charged battery or the AC power adapter The batteries are not user serviceable If a battery exceeds a tem perature or load threshold a non resettable fuse will ...

Page 19: ... ber only Use of another battery may present a risk of fire or explosion Keep away from children Avertissement Ne rechargez les batteries qu avec un chargeur conforme au SMBUS niveau 2 ou 3 Ne chauffez pas au dessus de 80 C Ne pas ouvrir la batterie ni ne la jeter au feu ou court circuiter elle peut mettre à feu exploser couler ou s échauffer causant des blessures personnelles Remplacez les batter...

Page 20: ...t will not charge the batteries Not powered through the universal power adapter 9968 232 4 Power Red 2 Power Black Ground 6 Power Black Table 2 1 Pin assignments for the connector and power cable Figure 2 2 Pins for the power cable left and instrument power connector right Connecting with the instrument Connect with the instrument using a web browser on a computer tablet or smart phone that is on ...

Page 21: ...the display panel if the network cable is connected l Fixed IP address of 192 168 10 1 if the internal Wi Fi is enabled 3 Press Enter to connect If you are unable to connect see troubleshooting Connection problems on page 5 1 1This product is capable of creating a Wireless Local Area Network WLAN The use of WLAN is restric ted in some regions and countries The illegal use of WLAN may be punishable...

Page 22: ...s on a network by displaying the network icon and the network assigned IP address If your local network also has Wi Fi you can connect to the instrument over the wireless network 2 Enter the hostname or IP address in a web browser address bar Both the hostname which is the instrument serial number and IP address are given on the display Type one or the other into the address bar l Hostname Enter t...

Page 23: ...e previous page 1 Click Options Settings 2 Click the Wi Fi tab 3 Set Wi Fi to Off or On 4 Click Update to apply the setting If you click away from the page without first clicking Update the setting will not be applied The Wi Fi status is displayed in the status bar and the instrument dis play panel Section 2 Getting started 2 7 Enabling and disabling Wi Fi ...

Page 24: ...twork cable is installed between the instrument network port and a port on a local area network l Wi Fi Status When Wi Fi is enabled indicated by the symbol the instru ment broadcasts a Wi Fi network with the same name as the instrument serial number and hostname l Battery Status Indicates the charge status A solid black battery indicates a full charge an outline indicates a discharged battery The...

Page 25: ...al RMS too high Measurements are invalid Red 64 Unregulated pressures or temperatures Measurements are invalid Red 128 Inlet clogged Triggered when the inlet is obstructed for 3 or more seconds When triggered the instrument turns off the pump and enters sleep mode Clear the obstructions and restart the instrument Red 256 Instrument not ready Measurements are invalid Red SVC Required This message m...

Page 26: ...ithin 3 seconds In sleep mode the instrument will power off the pump but maintain power to the heaters Sleep mode is to silence the pumps if for example you want to hear the birds singing while you walk between measurements To Exit Sleep Mode press the power button after waiting at least 5 seconds after the previous press Caution While in sleep mode the instrument will stop drawing in air which ma...

Page 27: ...m pad part number 6578 296 that protects the air inlet and outlet while it is packaged Keep the foam pad so you can use it to ship the instrument should the need arise Cover the air inlet and outlet with the blue caps that were provided with the instrument or scotch tape to keep dust from the filter Position the foam pad over the inlet and outlet wrap the instrument with plastic wrap place it in a...

Page 28: ...Section 2 Getting started 2 12 LI 7820 N O H O Gas Analyzer ...

Page 29: ...d phase adjuster and is exhausted through the air outlet In the optical bench the pressure is drawn down to about 40 kPa When the instrument is powering down air is circulated in a closed loop through the desiccant to ensure that air remaining in the system is free of moisture preventing condensation when the instrument is powered off Figure 3 1 Simplified flow schematic of the gas analyzer During...

Page 30: ...ompression fitting The nut and ferrule sets are in the accessories kit Caution Be very careful when working near standing water If water is drawn into the air inlet the instrument will have to be repaired at the factory Figure 3 2 When connecting a tube to the air inlet use steel ferrules to form a good seal Tighten the nut over the ferrule set until it is finger tight For metal and plastic tubing...

Page 31: ...have questions about your application A typical sampling application will use the LI 7820 to subsample a gas from a main sample line Air passes a single time through the gas analyzer before it is dis charged Air supplied to the sample inlet should be between ambient and 35 kPa 5 PSI above ambient If the pressure is higher than that install a 30 cm vent in the sample line to ensure that air from th...

Page 32: ... protocols see Downloading a data file below and l MQTT Message Queuing Telemetry Transport see Communication with the MQTT protocol on page 7 1 Downloading a data file To retrieve data from the instrument click Options Export Specify a date range and time period Dates are displayed as YYYY MM DD Time options are given in a 24 hour clock 00 00 through 24 00 Click Export The web browser will prompt...

Page 33: ...ing columns and one called DATAU which gives the units for the corresponding columns DATAH DATAU Description SECONDS secs Seconds past the universal epoch Unix time NANOSECONDS nsecs Nanoseconds of the seconds NDX index A count of scans At four scans per second the value increases by four counts per second DIAG diag Diagnostic code see Status codes on page 2 9 REMARK The remark entered in the Rema...

Page 34: ...ect corrupted data lines Time data and diagnostics The time data diagnostics and remark are given under the header The relationship between Unix Epoch time and the time stamp The instrument measures time based upon the number of seconds past the Unix epoch GMT Thursday January 1 1970 12 00 00 AM This value is represented in the Seconds column of the data set You can easily convert the Unix epoch t...

Page 35: ... 61 cm 13 by 24 with 18 cm 7 of vertical clearance The instrument dimensions are given in Figure C 1 on page C 2 Be sure that the vents on the sides are not obstructed Allow 2 to 3 cm 1 inch of clearance on either side of the vents Ensure that air can flow freely around the case Section 3 Applications of the LI 7820 3 7 Installing the instrument in a rack mount ...

Page 36: ...Section 3 Applications of the LI 7820 3 8 LI 7820 N O H O Gas Analyzer ...

Page 37: ...ent settings Home page When you first connect to the instrument it will display a home page with meas urements graphs and options Indicators and buttons You ll see the instrument serial number and status in the upper left Normal oper ation is indicated by a green dot A warmup or other status is indicated by an exclamation point in a yellow or red dot beside the instrument name 4 1 LI 7820 N O H O ...

Page 38: ...to determine which is depleted Wi Fi and network status information see Wi Fi on page 4 8 Click to view the Options menu Click to return to the home page only visible when not on the home page Remarks Remarks are user entered information 15 characters maximum that is recorded in the dataset along with other data in the database including gas densities and dia gnostics For example you might enter s...

Page 39: ... can adjust the plotted time range with a slider or by typing in the number of seconds in Graph Range Seconds Click Reset to restore the default range of 300 seconds Click to display the entire history of measurements of this variable Click to hide or show anomaly stripes to indicate when a measured value exceeds a threshold see Thresholds on page 4 15 Click to lock the graph to the current view C...

Page 40: ...Fi and connection to peripheral instru ments These are described below Software Under Settings Software you can check the software version check for updates and change the language setting Click Check to check for software updates The instrument must be online to check See Software updates on page 6 7 for update instructions 4 4 LI 7820 N O H O Gas Analyzer ...

Page 41: ...panish and simplified Chinese languages The language set ting is retained in the web browser not the instrument If you connect with a dif ferent browser or different computer or if you clear your browser cache the default language setting will be applied English Section 4 Software overview 4 5 Software ...

Page 42: ...g at all times to prevent clock drift When selected the instrument will set its clock according to the local network time When not selected you must enter the desired time manually The Auto Sync options are l NTP Network Time Protocol A time protocol designed for low cost time syn chronization between computers and devices You can use the default settings of auto or select an NTP server either fro...

Page 43: ...h NTP or PTP clocks If Auto Sync is disabled or the instrument is not online expect the clock to drift up to several seconds per month or more Time zone Here you can select a time zone that applies an offset to the Unix epoch time If you change any of the time settings click Update to apply the changes Network Under Settings Network you configure the network settings If you change the settings cli...

Page 44: ... use some thing like 172 24 1 nn where the values represented by nn are octets that uniquely identify this instrument on the network l Subnet Mask Typically 255 255 255 0 l Default Gateway Set the first two octets to match those of the IP address Wi Fi Under Settings Wi Fi you can configure the wireless network settings including whether the wireless network is on or off and which channel it uses ...

Page 45: ...l for com munication over the wireless network When there are many Wi Fi networks avail able in one location you can assign a specific channel for a more reliable connection LI 8100 A Under Settings LI 8100 A you configure communication with the LI 8100 A instrument IP Address To connect with an LI 8100A enter the LI 8100A IP Address here Additional details are provided in an application note http...

Page 46: ...date that the span was set Last the span value Weight the multiplier that is set when you span the N2O measurement and the N2O Concentration ppb entered in the previous span Do not change the settings unless you are certain that your actions will improve the performance of the instrument See Instrument calibration on page 6 1 Restore Span Zero allows you select a previous zero and span setting Fac...

Page 47: ...n Normal operation is indicated by green bubbles An exclamation point inside one or more bubbles indicates that the instrument is not in a normal operating state Typically these are displayed when the instrument is warming up and the status message will disappear when the warmup is completed Click a bubble to view the status message See Status codes on page 2 9 for more information If your instrum...

Page 48: ...ithin the green part of the dial l Cavity Pressure is measured in the optical cavity The instrument operates around 40 kPa typically If the values are colored red that indicates that the instrument is unable to regulate the cavity pressure Normally this value is within 1 kPa of the setpoint l Phase Pressure refers to the pressure for the phase adjuster volume If red the instrument is unable to reg...

Page 49: ...and in a warmup state Normally this is between 51 5 C and 57 5 C l Cavity Temperature is the optical bench temperature If red the instrument is either too hot and unable to regulate the cavity temperature or too cold and in a warmup state Normally this is between 52 C and 58 C l Laser Temperature is the temperature of the diode laser If red the instrument is unable to regulate the laser temperatur...

Page 50: ...Layouts You can customize the graphical layout If for example you are only interested in viewing N2O measurements you can select a layout that displays one gas and then select the gas of interest 4 14 LI 7820 N O H O Gas Analyzer ...

Page 51: ...icate if the measurement is outside of the threshold on the graph with anomaly stripes click Hide Show Anomaly Stripes and the status by color coding the reported values You can change the colors by clicking Low Color Middle Color or High Color on the Thresholds page Thresholds are for display only they are not recorded in the data file Export Data are downloaded from the instrument using the Down...

Page 52: ...Section 4 Software overview 4 16 LI 7820 N O H O Gas Analyzer ...

Page 53: ...upon the device manufacturer l The web browser may continue to try to resolve the hostname to an IP address unsuccessfully In this case simply enter the instrument fixed IP address into the address bar For trace gas analyzers it is 192 168 10 1 Unable to connect with the instrument over a wired connection Network cable disconnected Check both ends to be sure it is connected to the instrument and t...

Page 54: ...rument s IP address given on the display If the IP addresses are not compatible see Table 5 1 below you will not be able to connect until you have changed one or both IP addresses Device IP Address Issue Potential Solution LI 78xx 172 24 1 1 Same IP address the last set of octets must be different Change PC IP address to 172 24 1 2 PC 172 24 1 1 Device IP Address Issue Potential Solution LI 78xx 1...

Page 55: ...mple causing communication to time out Wireless networking turned off If you are attempting to connect over wireless be sure it is enabled in the software The display will show a wireless network symbol when enabled If wireless networking needs to be enabled connect with a wired network connection and enable it as described in Wi Fi on page 4 8 Computer or mobile device connected to the instrument...

Page 56: ...ir inlet filter on page 6 4 Otherwise unstable pressure readings may indic ate that the pump is failing Contact technical support if the issue is not resolved by replacing the filter Gas density measurements appear to have oscillations Regular periodic oscillations in the data may appear in circumstances where there are vibrations that are effectively coupled to the instrument sampling frequency I...

Page 57: ...e settings the browser may receive overlapping time information Refresh your web browser to reload the display The issue should be resolved Data are always logged with the Unix time Status and warning messages During warmup and any time the instrument detects a problem it will issue one or more status messages including a message that says SVC Required This is nor mal during warmup Typically warmu...

Page 58: ...trument has drawn water dust or debris into the inlet filter causing a clog In either case power off the instrument clear the obstruction replace the filters see Replacing the air inlet filter on page 6 4 and power the instrument back on You must restart the instrument to resolve code 128 5 6 LI 7820 N O H O Gas Analyzer ...

Page 59: ... like a slope the m in y mx b The zero is a spectral baseline Adjusting the zero changes every measurement the relationship is non linear Adjusting the span changes the slope Calibration gases should be at a pressure between ambient and 35 kPa 5 PSI above ambient pressure We recommend installing a 30 cm vent before the air inlet to vent the excess pressure and prevent diffusion of ambient air into...

Page 60: ...itialize properly 1 Connect a tank of N2O in dry air or manufactured air to the air inlet Figure 6 1 on the previous page The span gas will work for this 2 Set the pressure between ambient and 35 kPa 5 PSI above ambient 3 Observe the measurements on the home screen until the N2O has stabilized The slope will be near zero 4 Being careful to avoid introducing any H2O into the air switch to the zero ...

Page 61: ...ick Span N2O Recovering from a bad calibration In the event that an attempt to zero or span fails to work as intended you can restore previous zero and span settings by selecting the file and clicking Restore Factory Reset reloads the factory original zero and span calibration parameters Section 6 Maintenance 6 3 Recovering from a bad calibration ...

Page 62: ...thread locking compound which will make them difficult to remove 3 Remove the O rings the filter support disks and the filter Use a toothpick to work them out 4 Inspect the O rings and replace them if they are damaged or compressed 5 Install the replacement filters and reassemble the system Install two filters part number 9978 234 between the support disks The two metal discs support the filter s ...

Page 63: ... in coughing and or sore throat PROLONGED OR REPEATED EXPOSURE TO DUST MAY CAUSE PULMONARY PROBLEMS INGESTION MAY CAUSE GASTRIC DISTURBANCES Advertissment Peut causer une irritation PEUT CAUSER UNE IRRITATION DE LA PEAU PEUT CAUSER UNE IRRITATION DE LA VOIE RESPIRATOIRE PEUT CAUSER DOULEURS NAUSÉE VOMISSEMENTS ET DIARRHÉE Peut entraîner une toux et ou un mal de gorge L EXPOSITION PROLONGÉE OU RÉPÉ...

Page 64: ...packet of silica gel beads in the accessories kit 7 Fill the column with fresh silica gel beads There may be a little more than is needed Dispose of the extra silica gel beads 8 Reassemble the filter and caps connect the tubes and tighten the screw clamps securely Important Tighten the clamp screws securely The clamps hold the caps onto the tube the caps hold the silica gel beads in the tube If th...

Page 65: ...ater applic ation and install it on your computer Windows only Launch the application It will display a list of all LI 7810 LI 7815 and LI 7820 instruments on your network The instrument that you want to update must be connected to your network or computer Select one to update and click Update Software The update will take sev eral minutes The instrument will restart when the update is complete Se...

Page 66: ...Section 6 Maintenance 6 8 LI 7820 N O H O Gas Analyzer ...

Page 67: ... These tutorials are for novice users Terminology Here we provide a simple summary of terminology used in MQTT These terms are described in greater detail by other online resources l Server The Trace Gas Analyzer is a server that sends information l Client The computer or device that is receiving information The server e g Trace Gas Analyzer can communicate with any client device that is configure...

Page 68: ...terminal program The instrument can be controlled from a terminal program macOS or command prompt program Windows With trace gas analyzers that means you can set the zero and span calibrations read the calibrations and read data with diagnostics In the following section we describe how to perform these basic functions This tutorial uses Eclipse Mosquitto an open source message broker from the Ecli...

Page 69: ...squitto_sub h 172 24 82 41 t licor niobrara output concentration l mosquitto_sub launches the application to subscribe l h specifies a host the Trace Gas Analyzer followed by the instrument IP address l 172 24 82 41 is the instrument IP address You can also enter the host name Both are given on the instrument display l t specifies that you want to subscribe to a topic l licor niobrara output conce...

Page 70: ...wed by the instrument IP address l 172 24 82 41 is the IP address You can also enter the host name Both are given on the instrument display l t specifies that you want to subscribe to a topic l licor niobrara cfg Start_Peak_Base_Line_Cal is the topic and hier archy l m specifies that you are sending a message from the command line l 1 is the message This command initiates the baseline calibration ...

Page 71: ... IP address You can also enter the host name Both are given on the instrument display l t specifies that you want to subscribe to a topic l licor niobrara system N2O_Span is the topic and hierarchy for the LI 7820 l m specifies that you are sending a message from the command line l N2O tank in ppb is the N2O concentration in PPB This initiates the span calibration in the LI 7820 The span is implem...

Page 72: ... reboot This initiates the restart cycle beginning with a purge of the optics Powering off the instrument To power off the instrument send the following command mosquitto_pub h 172 24 82 41 t licor niobrara system shutdown m shutdown This initiates the shutdown beginning with a purge of the optics There is no com mand to power on the instrument remotely 7 6 LI 7820 N O H O Gas Analyzer ...

Page 73: ...am will issue a few replies as it completes the installation Now your computer should have all of the files needed to communicate with the instrument Configuring paho mqtt in Mac or Linux Although Mac computers include Python by default you need to install some addi tional libraries This is done in the command line interface 1 Launch the terminal program Type CMD Space to open the search bar Type ...

Page 74: ...tr mid str granted_qos def on_message client userdata msg msg str msg payload print msg client paho Client client on_subscribe on_subscribe client on_message on_message client connect 172 24 82 41 1883 client subscribe licor niobrara output concentration qos 1 client loop_forever 2 Change the IP Address next to client connect to match that of your instrument The default port is 1883 so leave that ...

Page 75: ...ating success 2 Create the python script to save the data Copy the following into a text file and save it to your computer s desktop or another directory with a py extension like import datetime py import datetime import requests import socket slno tgXX 01009 local ip socket gethostbyname slno dl1 http ip 8080 ExportAdvancedData tmin dl2 tmax tmz 06 00 dt datetime datetime 2019 5 10 0 0 0 end date...

Page 76: ...atetime timedelta minutes 30 change the value 30 to the number of minutes you want E Set the directory to save the data In with open C User s User Name Documents flnm wb specify the directory 4 Start the script from the terminal program or command prompt In the terminal program change to the directory that has the py file saved earlier Type cd desktop on Mac or type cd C Users User Name Desktop if...

Page 77: ...ser and optical bench that is tied to a pressure control mechanism Changing the pressure of that volume alters the refractive index which subsequently modifies the phase of the laser The instrument ramps the laser drive current so the laser scans a range of wavelengths that span absorption features of the gases A fraction of the photons are allowed to leak from the cavity back into the laser creat...

Page 78: ... to normalize the measured signal Absorption is computed at each resonance mode by comparing the normalized sample photodiode signal with the reference photodiode signal The concentration of each gas is then determined by using a fitting algorithm that compares the meas ured absorption spectrum with internally stored high resolution spectrum Figure A 2 Example of a scan showing the absorption feat...

Page 79: ...ts ou l exécution des procé dures autres que celles spécifiées ici peuvent entraîner une exposition dangereuse aux radiations The LI 7820 is certified as a Class I laser product No hazardous radiation is emit ted from the instrument Any laser radiation emitted is below the Class I laser lim its during all phases of user operation The laser emits internally only at approximately 1651 nm and has a C...

Page 80: ...Additional safety information Figure B 1 The Class 1 laser safety label is affixed to the back of the case Figure B 2 The laser radiation safety label is inside the instrument case B 2 LI 7820 N O H O Gas Analyzer ...

Page 81: ...ter Frequency mHz Upper Frequency mHz 1 2401 2412 2423 2 2406 2417 2428 3 2411 2422 2433 4 2416 2427 2438 5 2421 2432 2443 6 2426 2437 2448 7 2431 2442 2453 8 2436 2447 2458 9 2441 2452 2463 10 2446 2457 2468 11 2451 2462 2473 Radio transmission power is given in Table B 1 below Network Type Transmission Power 802 11b 10 5 dBm 802 11g n 11 dBm Table B 1 Radio transmission power Appendix B Addition...

Page 82: ...r local regulations to determine how to safely dispose of the batteries Advertissment Les batteries lithium ion peuvent causer des dommages à l environnement ou endommager la santé humaine si l on se débarrasse d elles de man ière inappropriée Ne vous débarrassez pas des batteries dans des déchets municipaux non triés ou dans un incinérateur Plusieurs localités ont des installations de recyclage d...

Page 83: ...move the four screws that secure the electronics shroud Being careful to avoid straining the Wi Fi antenna it is glued to the shroud move the shroud to the side The battery is near the middle of the instru ment The battery is held in with friction Press it out Insert a replacement battery with the positive pole facing up Figure B 3 Carefully lift the shroud as shown to avoid straining the Wi Fi an...

Page 84: ...Appendix B Additional safety information B 6 LI 7820 N O H O Gas Analyzer ...

Page 85: ...load under normal operating conditions Operating Pressure Range 70 to 110 kPa Connectivity Ethernet and Wi Fi not available in some countries Wi Fi Compatibility 2 4 GHz 802 11a b g n ac Power Requirements Pins 1 and 5 24 VDC Input 6 Amps Pins 3 and 4 10 5 to 33 VDC Input 8 Amps Power Consumption Steady State Operation 22 Watts Warmup 10 5 to 33 VDC power supply pins 3 and 4 Up to 100 Watts with b...

Page 86: ...ppb with 1 second averaging 0 20 ppb at 330 ppb with 5 second averaging H2O Measurements Range 100 to 60 000 ppm Precision 1σ 45 ppm at 10 000 ppm with 1 second averaging 20 ppm at 10 000 ppm with 5 second averaging Figure C 1 LI 7820 dimensions Clearance is required for the power cable and tubing as well as 2 to 3 cm around the case vents C 2 LI 7820 N O H O Gas Analyzer ...

Page 87: ...aged by act of God or other casualty 4 The purchaser whether it is a DISTRIBUTOR or direct customer of LI COR or a DISTRIBUTOR S cus tomer packs and ships or delivers the instrument to LI COR Inc at LI COR Inc s factory in Lincoln Nebraska U S A within 30 days after LI COR Inc has received written notice of the defect Unless other arrangements have been made in writing transportation to LI COR Inc...

Page 88: ...pply whether included by this contract or by law are limited to the time period of this warranty which is a twelve month period commencing from the date the instru ment is shipped to a user who is a customer or eighteen months from the date of shipment to LI COR Inc s authorized distributor whichever is earlier This warranty supersedes all warranties for products purchased prior to June 1 1984 unl...

Page 89: ...inese language 4 5 5 5 connecting 2 4 local area network 2 6 wireless 2 5 connecting a sample 3 3 connecting an air supply 3 2 connection issues 5 1 5 3 D data retrieving 3 4 data files about 3 4 DHCP 4 7 dimensions C 2 display panel 2 8 downloading data 3 4 dry down chemical 6 5 E English language 4 5 5 5 error codes 2 9 F files data 3 4 filter air inlet 6 4 I installing 3 7 IP address 5 2 L LAN ...

Page 90: ...laser B 1 SD card error message 2 9 serial number 2 8 set IP address automatically 4 7 settings 4 11 shipping the instrument 2 11 size C 2 software updating 4 4 software interface 4 1 software version 4 4 span calibration 4 10 Spanish language 4 5 5 5 spectroscopy 1 1 A 1 static IP address 4 8 status performance 4 11 status codes 2 9 storing 2 11 SVC required 2 9 T thermal enclosure temperature 4 ...

Page 91: ......

Page 92: ...al Offices LI COR Biosciences GmbH Siemensstraße 25A 61352 Bad Homburg Germany Phone 49 0 6172 17 17 771 envsales gmbh licor com LI COR Biosciences UK Ltd St John s Innovation Centre Cowley Road Cambridge CB4 0WS United Kingdom Phone 44 0 1223 422102 envsales UK licor com LI COR Distributor Network www licor com env distributors 984 19432 03 2021 ...

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