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 35

5.  Connecting sensors/signals to the datalogger 

5.1  Wiring up thermistor sensors 

Individual  plug-in  terminal  blocks  with  cable  restraints  are  provided  to 
make the  connections  to  the inputs  on  the  datalogger.  Thermistors  often 
have no designating letters, since they have no polarity. 
 

o

c

v

thermistor

sensor

thermistor

sensor

o

o t

t

thermistor

sensor

o

c

v

t

thermistor

sensor

451/851

 

Note: The 

‘-’ denotes the ground connection. This should be connected to 

the cable screen, if any. 

5.2  Wiring up platinum resistance sensors 

Individual  plug-in  terminal  blocks  with  cable  restraints  are  provided  to 
make  the  connections  to  the  inputs  on  the  datalogger.  1000  Series 
loggers support both 3 and 4 wire PT100 sensors, and may be marked in 
either of the two ways shown below. 

 

3 wire connection

sensor

4 wire connection

sensor

 

 

N.B. It is essential for 3 wire sensors that the resistances of all the 
connections are equal, i.e. the wires used for these connections should be 
of the same material, gauge and length. This allows the circuit to cancel 
the effects of lead resistance on the sensor measurement. 

Summary of Contents for Squirrel 1000 Series

Page 1: ...re about the functions of the datalogger 13 4 1 The LOG function 13 4 2 The METER function 15 4 3 The REVIEW function 16 4 4 The TIME and date function 17 4 5 The delayed START function 17 4 6 The INT...

Page 2: ...channels 50 9 1 Channel Selection 50 9 2 Pre setting the Temperature 50 9 3 Choosing the Calibration Point 51 9 4 Calibrating the Midpoint pH7 0 51 9 5 Calibrating the Slope 52 9 6 Current Consumption...

Page 3: ...age 62 13 Technical data 63 13 1 Inputs ranges and resolutions 63 13 2 Specification 64 14 Connectivity 65 14 1 Signal connector 65 14 2 Output connector for connection to a PC 65 Declaration of Confo...

Page 4: ...e logger but some functions can only be accessed through Darca These include Scaling EU units in a channel SMS Alarm operation For more information on using Darca consult the document TM1020 Overview...

Page 5: ...gger is currently logging then the first reading in the current run is displayed 2 4 TIME date Displays the real time and date on two lines The 24 hour clock may be displayed in the appropriate countr...

Page 6: ...which could include engineering units if these have been set up by Darca This function also displays how many channels have been selected to record 2 10 STAT status This function displays the followin...

Page 7: ...ars T I M E 1 0 4 3 1 1 H O L D T O C H A N G E Hold set button and cursor will appear the clock will stop T I M E 1 0 4 3 1 7 d a t e 2 5 1 2 9 4 Press select to move cursor T I M E 1 0 4 3 1 7 d a t...

Page 8: ...0 Press select to move cursor I N T l o g 0 0 0 0 3 0 s a m p l e 0 0 0 0 0 0 Press set to change value I N T l o g 0 0 0 0 3 5 s a m p l e 0 0 0 0 0 0 This example changes the logging interval from...

Page 9: ...s until you have configured at least one channel In this case pressing the function key will only display the following message C H A N N E L S E T U P N O N E S E L E C T E D Please proceed to the fo...

Page 10: ...ropriate voltage current range is then selected from the existing hardware ranges e g 0 1 V In the above example 0 50 m s 0 1V and the display in METER mode will show readings in m s All data in this...

Page 11: ...ygroclip S3 HC2 These probes plug into any voltage current input selected using the CHANNEL SETUP function Press and hold set for 3 seconds to change an unused voltage current channel to the default E...

Page 12: ...12 3 6 Stop logging Press function to wake up the logger L O G o n u s e d 1 2 3 Hold set to stop logging L O G o n H O L D T O S T O P L O G o f f u s e d 1 2 3...

Page 13: ...sed see 0 the logger waits for a specific time and date to start logging and the following is displayed L O G w a i t i n g u s e d 0 Alternatively this may indicate that externally triggered recordin...

Page 14: ...1 2 3 4 5 N B you can only start and stop logging when the display shows either of these screens 4 1 4 How to clear the memory The procedure for clearing the memory has been designed to reduce the ris...

Page 15: ...R c h 5 0 3 4 0 V M E T E R c h 7 5 2 9 L u x 4 2 1 Pulse count channels When viewing a pulse count channel in METER mode the display will show an accumulating total of pulse counts This total may be...

Page 16: ...R mode M E T E R c h 1 1 1 2 3 s 4 3 The REVIEW function The display shows the recorded value of the selected channel starting with the first reading in the most recent run or the first reading in the...

Page 17: ...ated The logger modifies the entries to the nearest valid setting and displays a warning that the initial entries were invalid For example the following would occur in UK date format i e DD MM YY T I...

Page 18: ...art time before commencing logging In this case the following message will be displayed S T A R T 0 0 0 5 5 5 d e l a y e d s t a r t N B Remember that you must also set the logger to start logging in...

Page 19: ...is shown on the bottom line and can be set between 1 second and 12 hours provided that a logging mode including averaging is selected M O D E l o g a v e r a g e M O D E l o g e v e n t a v e r a g e...

Page 20: ...used Eltek Squirrels with serial numbers 6000 and above will work at up to 38400 baud During downloading the number of blocks to be downloaded is displayed and this number changes after each successfu...

Page 21: ...during this interval The logger records the first readings as soon as logging is started although pulse inputs record a dummy value at this point Please see section 3 2 for instructions on how to chan...

Page 22: ...with the time and date of the event b readings are also taken and stored from all other channels which have been set to log c if a pulse channel has been selected then the number of pulses accumulate...

Page 23: ...23 voltage high contacts open contacts open contacts closed contacts closed high low low time event event event event event event event event...

Page 24: ...n averaged values of the selected channels to be recorded whenever an event occurs see 0 Pulse inputs record a dummy value when events occur and true accumulated values are only recorded after each re...

Page 25: ...adings will be recorded in only one run This will be of value if you need to analyse these triggered events on one time axis The time channel is selected automatically to log the time between recordin...

Page 26: ...available memory has been used Note that you may view remaining free memory at any time by entering the LOG function and pressing select see section 4 1 2 and the memory size may be restricted down t...

Page 27: ...f the channels Some of the channels may not be currently selected and these will be indicated as follows C H 5 n o t u s e d Holding down the set button will allow you to set up the channel C H 5 H O...

Page 28: ...nts such as types K and T thermocouples or 3 and 4 wire platinum resistance sensors For example a logger with thermocouple inputs will offer the following ranges C H 1 C 2 0 0 0 2 0 0 0 where the reso...

Page 29: ...t one pulse count channel except 451 851 loggers Typical applications are outputs from tipping bucket rain gauges optical meter readers etc Any sensor offering the following outputs can be monitored a...

Page 30: ...open voltage high The number 0 or 1 is called the state If you have selected to log in any of the event modes see section 4 8 6 then the last event channel will be automatically selected A typical ap...

Page 31: ...power supply S T A T e x t s u p p l y 8 9 V The logger can be used with an Eltek external DC power supply type MP12U if GSM modem use anticipated or MP12U5W in all other situations These are ultra lo...

Page 32: ...y allows you to switch the sensor on between 1 second and 60 seconds in 1 second increments prior to measurement all sensor power outputs will turn on together The maximum total current available is 5...

Page 33: ...and holding set S T A T d a t e f o r m a t Y Y M M D D S T A T d a t e f o r m a t M M D D Y Y 4 10 6 Language format selection S T A T l a n g u a g e E n g l i s h This displays the language format...

Page 34: ...gger 4 10 9 Temperature Units This function enables you to change the temperature units in the Squirrel between degrees Fahrenheit and Celsius If this is changed you must change the range using Channe...

Page 35: ...nnected to the cable screen if any 5 2 Wiring up platinum resistance sensors Individual plug in terminal blocks with cable restraints are provided to make the connections to the inputs on the datalogg...

Page 36: ...sensor output v v c o sensor output sensor power Note if the cable used has an independent screen this may be connected to the ground terminal which is marked o 5 4 Wiring up sensors to current chann...

Page 37: ...end on the state of the internal batteries or the voltage of the external power supply if present Some models have the option to change the sensor power to 5V DC 0 1 This is dealt with in section 4 10...

Page 38: ...ent sensors Rogowski coils Voltage Transducers and Current Transducers can be connected to any of the AC voltage inputs Some inputs also allow thermistors to be connected For 1010 1020 electricity log...

Page 39: ...free contact input e g relay the contact debounce circuit must be connected This involves linking the pin to the s pin s s sensor output volt free contact Note the connection is ground and should be c...

Page 40: ...ute an event The above diagram shows all events being monitored using contact closures but events may also be monitored using changes in voltage levels see 0 1000 Series loggers with additional event...

Page 41: ...g can be started or stopped by an external signal This external signal can be in the form of a voltage or a contact and should be connected between pin 14 and common ground See 4 8 11 for further info...

Page 42: ...form multiple runs if memory is in continuous mode reset pulse count while logging is in progress change date and time while logging change start date and time while logging change log and sample inte...

Page 43: ...earch for SRAM in Windows Help for information on how to do this 7 2 1 Formatting the card Open Darca s Memory Card Utils feature it is accessed from the File menu Your SRAM card will appear under the...

Page 44: ...e following C A R D p r e s e n t H O L D T O C L E A R If the size of the card is not displayed it is due to one or more problems The nature of the problem is clearly stated on the display C A R D p...

Page 45: ...e m o r y If there is any Squirrel data present in the card then the display will show the following C A R D h o l d s d a t a u s i n g m e m o r y By default the internal memory is used If you have...

Page 46: ...ear It is possible to copy to the card while the Squirrel is logging to its internal memory though this may take longer Note that this function cannot be accessed while the Squirrel has been set up to...

Page 47: ...47 to be stored in with the second Browse button Click the Convert button to copy the data from the SRAM card and store it on your PC as the chosen DAT file...

Page 48: ...logging the Squirrel monitors each selected channel for peak values This function allows the user to review the maximum logged value on each channel M A X I M U M c h 1 2 4 8 8 V Along with the maxim...

Page 49: ...ermistor 25 0 to 125 0 C 0 1 C 9 17 Pulse count 0 to 65 000 1 0 to 650 000 10 10 18 Digital 0 to 255 State 00000000 to 11111111 8 3 Making connections to the datalogger It is possible to connect many...

Page 50: ...will perceive this as an error and switch the range to use the pre set compensation In this situation the display will show INVALID CHECK to alert the user that this has happened C H 9 p H c h 1 0 0...

Page 51: ...ow the calibration settings see below Place each probe individually in a pH7 buffer solution and allow it time to settle the time this takes will depend on the probe and how it has been stored or used...

Page 52: ...h the solution that is being used then the slope value in the STAT function must be changed appropriately see above If it reads O RANGE then the pH input is too far out of range of the preset value fo...

Page 53: ...a very high or very low pH may take a while to settle Occasionally the output of a probe may continue to wander never really settling on a value This is an indication that the probe has expired and sh...

Page 54: ...elect until the required channel is displayed Then press and hold set to enter the edit mode L O W A L A R M c h 1 H O L D T O C H A N G E A lower alarm threshold will appear for editing The value use...

Page 55: ...is triggered when the alarm is exceeded for the delay interval The logger must be logging for an alarm to be reported Meter When metering the display will show two asterisks when you are viewing a ch...

Page 56: ...ge it is not averaged as 0 5V dc as this would cause an erroneous readings under certain conditions e g When the direction varied around North say 375 to 5 the mathematical average would be 180 which...

Page 57: ...tion other than LOG can be selected This is true even if the interval is for example 8 4 seconds If the interval were 8 seconds or 9 seconds this restriction would not apply as the logger would behave...

Page 58: ...Export and choose Generate Elapsed Time Column 11 3 Darca Contact It is not possible to contact the Squirrel for either controlling or downloading while it is logging in fast logging mode Logging must...

Page 59: ...inals are connected through a 1MW resistor network to the datalogger ground At all other times both terminals are floating Datalogger ground may become connected to mains earth ground e g via a mains...

Page 60: ...at one of the following procedures is used to change the batteries otherwise memory and logger settings may be lost Stop logging remove the batteries and wait at least 2 minutes before fitting new bat...

Page 61: ...must be removed one is hidden under a battery contact in the battery box The top of the case can then be lifted off The 1A fuse on the board with the external power connector is for the external power...

Page 62: ...d to 260K reading memory by installing chip only Current standard memory is 260K reading memory Increasing memory to 500K or 1 000 000 or 2 000 000 reading memory is by substituting chip with appropri...

Page 63: ...2 F 0 1 C Impedance 100kW 200 to 450 C 328 to 842 F 0 2 C 200 to 1200 C 328 to 2192 F 0 5 C PT100 temperature P3 P4 200 to 100 C 328 to 212 F 0 1 C 200 to 400 C 328 to 752 F 0 2 C 200 to 600 C 328 to...

Page 64: ...th 8 channels recording every 5 minutes Clock accuracy 1 second day at 20 C Physical details Dimensions l 180 mm x h 120 mm x s 60 mm or d 85 mm depth may be greater depending on model Weight includin...

Page 65: ...11 Relay contact 1 12 Relay contact 2 13 Digital ground 14 External trigger input 15 Spare input 14 2 Output connector for connection to a PC The connector marked output is for communications between...

Page 66: ...8 The preferred adaptor is the NewLink USB Serial Convertor type NLUSB0039 which is available from Eltek Note Not all USB adaptors are compatible Ensure the device is installed correctly and make a no...

Page 67: ...m that this instrument conforms to the requirements of the EMC Directive 89 336 EEC amended 92 31 EEC and carries a CE mark indicating conformity Applied Standards Harmonised European Standard EN50081...

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