Miniature In Cell Amplifier for Strain Gauges
Contents
1. 30 v supply if required The strain gauge cable should be attached to the solder pads as illustrated 4 Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 Pa Figure 2 4 Connection Details for Best EMC Immunity 4 Core Screened Cable ICA4 SOURCE MODE CONNECTION C sires naz RS om N EMC Gland Terminating Screen Load Cell N B The PSU Com or Load common Chassis connection can be taken to ground Take note of the earthing arrangement The pad near zero trimmer MUST be bonded as tightly as possible to the chassis of the load cell This capacitively couples the common of the ICA4 electronics to the strain elements in the load cell which improve the EMC performance This connection should be made with 7 0 2 minimum cable with a maximum length of 12 mm 0 5 The ICA4 can be used with three wire cabling in both sink and source mode The only difference is whether the common end of the load is connected to ve sink mode or ve source mode This typical cable data is provided for information only The cable should have 2 x twin twisted cables Ideally with each pair individually screened and with an overall screen Table 2 1 Supplier UK Farnell 148 539 Individually screened twisted multipair cable 7 0 25mm 2 pair Tinned copper drain Individually screened in polyester tape Diameter 4 19 mm Impedance 54 Ohms Capacitance m core to core 115 pF amp core2. Zero Offset The ability to adjust the gain of a process or strain meter so that a specified display span in engineering units corresponds to a specified signal span constant input is applied Strain Gauge The Strain Gauge is a resistance bridge device where the bridge value alters linearly and proportionally to the force exerted on it be it pressure torque or load The ICA is designed to convert this change in the of the Strain Gauge to a proportional electrical signal The ICA1 amp 2 is essentially a type of Signal Conditioner that it conditions alters Amplifier the input signal from a strain gauge to an electrical output The Torque Transducer is one of a series of Strain Gauge sensors that the ICA input is designed to accept Wheatstone Bridge A network of four resistance s an emf source and a galvanometer connected such that when the four resistance s are matched the galvanometer will show a zero deflection or null reading Zero Zero is otherwise identified as OFFSET It relates to the proportional output to the sensor input Calibration of the ICA is determined by setting the Span Gain and Zero Offset Zero Adjustment The ability to adjust the display of a process or strain meter so that zero on the display corresponds to a non zero signal Zero Offset The difference between true Zero and an indication given by a measuring instrument See Zero Suppression Zero Suppression The Span is Offset from Zer
3. to screen 203 pF UK Farnell 585 646 Individually screened twisted multipair cable 7 0 25mm 3 pair Tinned copper drain Individually screened in polyester tape Diameter 6 86 mm Impedance 62 Ohms Capacitance m core to core 98 pF amp core to screen 180 pF UK RS 367 533 Braided screened twisted multipair cable 7 0 2mm 1 pair Miniature twin round Diameter 4 8 mm Impedance 62 Ohms Capacitance m core to core 120 pF amp core to screen 210 pF If possible segregate the signal cable from Power Cables allow a 1 metre 3 foot distance from such cables Do not run signal cable in parallel with power cables and cross such cables at right angles The earth connection conductor should have sufficient cross sectional area to ensure a low impedance path to attenuate RF interference Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 5 Output Connections The ICA4 analogue output is 4 to 20 mA Other modules offer DC voltages The DC current output supports both sink and source modes of operation A link provides the means of selecting the desired mode See Figures 2 2 and 2 3 for details In Source mode the ve end of the load is connected to the ICA4 output and the current is sourced by the ICA4 output via the external supply through the load towards ground OV This mode has the advantage that the negative output connection is common to the load cell Excitation terminal In
4. Gain 216x R 306 9 Ohms Used preferred value 300R e g 3 For 5 0 mV V Gain 21 6x R 3204 Ohms Used preferred value 3k3 or 3k24R E96 Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 7 Chapter 4 Calibration Figure 4 1 Connection Details for Calibration Load Cell or Load Cell For optimum EMC performance connect to Load cell chassis Voltmeter Display 1 Turn both potentiometers fully clockwise Now turn the S potentiometer seven turns anti clockwise mid way 2 Apply the low calibration conditions weight force or mV V Set the output to approximately 4mA using the Z potentiometer Note the exact reading 3 Apply the known high calibration conditions ideally between 75 and full scale and adjust the S potentiometer to give the required increase in output current for the known input e g 16mA increase for 4 20mA final calibration 4 Apply the low calibration conditions again and note the new value Apply the high conditions and re adjust the S potentiometer for the required change 5 Repeat steps 2 and 3 until the span is correct 6 Apply the low calibration conditions and adjust the Z potentiometer for the required output reading 8 Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 Chapter 5 Troubleshooting 1 No Output Check power supply is present and the correct polarity Check the output connections are correct with no open circuit conn
5. ICA4 Miniature In Cell Amplifier for Strain Gauges www mantracourt co uk User Manual Instructions MUA ME COURT ELECTRONICS LIMITED ICA4 Manual Contents Chapter 1 Introduction to The ICA Range cccccceseesseseseeeseeeseenseseeneesesesneeseseeeenseeesenseeseenens 2 Figure T1 Block Deet kenge deed sde eOtadensessncedesaagehnsstagedeassencgdes vageeashe 2 Chapter 2 Installing The ICA4 oc cecesseeeeeseeeeeeeeeeeseeeeeeeeseeeeeeeseseseeeseeeseeeseseseeesesesneeseeeesnanes 3 Pre IMStall tho m ie beta TE aabebeste tl tenn a a a a aeaaaee 3 Foure 2 NW Ru ET 3 Power GonNe Ctons een eenz ARENS Eed ees EE geg A Power Connections eea a Age Eed See Deeg a aa eaaa 4 Figure 2 2 Connection Details for Source Current esssessessesrirsserrrsserrrssrtrrssttrnssrrrnssrenn 4 Figure 2 3 Connections for Sink CUMENbes erario aai eao EA AREA 4 Figure 2 4 Connection Details for Best EMC Immumfty ee cceeeeeeeeeeeeeeeeteeeeeeneeeeeeaes 5 ABIGI 24 A EE recess Sh itclahencbiatt E ty Mts E EE tates 5 OUTPUE CONNECTIONS ode ees Hecke adslettcehineuer th a a aaa aat tated a a a ees denge 6 Chapter 3 Setting Gain Resistor cceccseseeeeeeeseeeeeeeeneeenseeneeseseeneesaesesneesesesneesesesneeeenesnanens 7 Table STAF AUMAR OOR R TROTA 7 Chapter 4 Calibratiom eu re inona ananena aatia aaea eaaa aae Ea a aaia eea Get AAE ERATA AEE la cape A ACAN EEEa 8 Figure 4 1 Connection Details for Calibration ce ceccceeeeeeeeeeneeeeeeeenieeeeeenaeee
6. INEERING UNITS Accuracy 1 part in half a million Temperature compensated Unwanted Signal noise filter Sensor specific calibration Elimination induced noise on signals In the interests of continued product development Mantracourt Electronics Limited reserves the right to alter product specifications without prior notice 95 Doc No ME 0131 MD 3D Code No 517 163 Issue 1 1 27 06 02 Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 15
7. Sink mode the ve end of the load is connected to the internal ve supply on the ICA4 and the ve end is connected to the ICA4 output The current through the load is sunk by the ICA4 towards ground OV N B In this mode neither connection to the output load is electrically common to the load cell Note If the ICA4 is required to operate in source mode common negative as per the Figure 2 2 then the above 4 wire cabling should be adhered to in order to provide the ICA4 with maximum protection If however a 3 wire cabling installation is required unavoidable the on board protection circuit will limit the fault current in the load to approximately 55mA in the event of the negative supply connection becoming open circuit D Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 Chapter 3 Setting Gain Resistor The ICA4 4 to 20mA In Cell strain gauge amplifiers is supplied un calibrated but optimized for a sensitivity of 2 5mV V To accommodate other sensitivities the gain resistor R as shown in Figure 2 2 can be changed according to the following formulae N B a high quality component e g 1 50 ppm metal film device should be used for optimum performance It may be necessary to use an E96 value for optimum trim range Table 3 1 ICA4 4 20mA Gain 108 R 66 000 Ohms required Gain 1 mV V e g 1 For 2 5 mV V Gain 43 2x R 1564 Ohms Used preferred Factory setting value 1k6 e g 2 For 0 5 mV V
8. d remove from service It is always wise to check a known good ICA against the problem Installation before rejecting the suspect ICA 10 Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 Chapter 6 Product Care A worn out component excessive use in harsh environments an overly zealous operator regrettably some circumstances necessitate repair At Mantracourt Electronics Ltd we can t guarantee that a product will never require repairing We can however promise a repair service of exceptional quality one which is governed by a rigorous procedure Detailed below is our pledge to you a defined set of ground rules and procedures to which we will adhere All we ask in return is that you assist us with our procedure such that we can maintain our promise to you Please note that warranty repairs may not be available on overdue accounts and that a strict interpretation of our conditions of trading invalidates warranty claims where late payment has occurred Please refer to Customer Repair Service Procedure document contact your supplier for a copy In the unlikely event you have problems with the ICA module we would advise that you take the following precautions The unit is installed as instructed Recommended spares are kept in stock We can assist Sufficient expertise available for first line maintenance Routine maintenance checks are performed annually is recommended The necessary documentation for t
9. ections Check terminations ensure there are no dry joints Check the sensor is connected typically reading 350 Ohm across output amp with the power off e Check the Excitation voltage is correct f Check the load is connected and is not open or short circuited g Check Span and Gain calibration a b c d 2 Low Output This is when an output is present but not of sufficient magnitude to meet the required value Remember to allow for Tare Weight and ensure it is measured and allowed for in the output from the ICA a Check power supply is within specified limits i e is not low b Check the sensor is connected typically reading 350 Ohm across output amp with the power off c Check the Excitation voltage is at 8V dc d Check the calibration e Check the Zero offset is correct for the sensor this too is a common reason for low outputs 3 High Output This is when an output is present but higher in span or zero than expected High output is not normally a problem It is most likely to be incorrect connections and as such the output would be high and fixed a Check the sensor is connected typically reading 350 Ohm across output amp with the power off b Check the Excitation voltage is at 8V dc c Check the Zero offset d Check the calibration 4 Unstable Output This is when the output is unstable or varies The cause could be a poor installation or b a noisy environment Poor In
10. er ICA input is designed to accept Torque Sensor Load Cell and Temperature Transducers Proportional The Voltage or Current outputs are calibrated to be directly proportional to the Outputs input from the sensor The output is within the sensor limits taken as linear and no linearity compensation is required within the ICA Resolution The input corresponding to a one unit change in the least significant digit of the data acquisition display equipment Good resolution is not necessarily equal to good accuracy Sensing Element That part of the Transducer which reacts directly in response to the input Sensitivity This is the relationship between the change in Strain Gauge input to the level or magnitude of the output 12 Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 Signal Conditioner A circuit module that offsets attenuates amplifies linearizes and or filters the signal The ICA is essentially a Signal Conditioner more specifically known as a Strain Gauge Amplifier in that it CONDITIONS alters the input signal from a load cell to an electrical output Single Card The ICA has only the one Printed Circuit Board assembly on which all the Assembly components are mounted The assembly is then mounted inside an environmentally rugged enclosure Span Span is otherwise identified as GAIN It relates to the proportional output to the sensor input Calibration of the ICA is determined by setting the Span Gain and
11. he product is available to the maintenance personnel We recommend you keep on file as a minimum e This Manual The calibration figures for the attached sensors A record of the normal output if applicable A calibration record of the ICA A contact phone number from the supplier for assistance Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 11 Chapter 7 Glossary American Wire Gauge The total noise floor from all sources of interference in a measurement system independent of the presence of a data signal See Noise can be correlated to the actual value being measured CMR The ability of an instrument to eliminate the effect of AC or DC noise between Common Mode signal and ground Normally expressed in dB at DC to 60 Hz One type of CMR Rejection is specified between SIG LO and PWR GND In differential meters a second type of CMR is specified between SIG LO and ANA GND METER GND Common Mode The ability of an instrument to reject interference from a common voltage at its input terminals with relation to ground Usually expressed in db decibels Drift Change of a reading set point value over periods due to several factors including PM enenge in ambient emperatur time andine voltage o sa as rea Excitation The external application of electrical voltage current applied to a transducer for EECH Fine Adjustment Zero and Span calibration have a Fine Adjustment to give accuracy to the TT carat These are potent
12. ist for versions ICA1 amp 2 and the ICA3 Transducer SENSITIVITY of between 0 5 mV V and 30 mV V are possible It is optimised to 2 5 mV V This range covers most but not all strain gauges Sensitivity adjustment is achieved by a combination of gain span resistor R change and associated fine adjustment by potentiometer Similarly transducer ZERO can be compensated for in the module This adjustment is to compensate for slight errors in the strain gauge and not to offset tare Mantracourt s SGA Strain Gauge Amplifier covers a range from 0 06 mV V to 30 mV V and its 79 offset can provide tare compensation 2 Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 Chapter 2 Installing The IC AA Pre Installation See Specification Details in Chapter 8 for details of Environmental Approvals Carefully remove the ICA unit from its shipment box Check that the unit is complete and undamaged Check The Model Type 1 2 3 or 4 they look similar The ICA units can operated in any industrial environment providing the following limits are not exceeded Operating Temperature 40 C to 85 C Humidity 95 non condensing Storage temperature 40 C to 85 C The following installation practices are advised Minimise vibration Do not mount next to strong electrical fields transformers power cables Ensure easy access to the module Install electrical protection device as the unit is not internally fused Always ensu
13. o Zero Suppressed such that neither limit of the Span will be Zero For example an instrument which measures a load of a 100kG Span from 400kG to 500kG is said to have 400kG Zero Suppression BIS REENEN Alternating Current PoC Direct Current Hz Letz Frequency kilohertz Frequency mw Smis EE AC DC Hz CA mV Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 13 Chapter 8 Specifications for ICA4 Load Cell Amplifiers Table 8 1 Output From the ICA4 4 20mA Parameter Minimum Typical Maximum Units Power supply reverse protected Bridge excitation Bridge resistance Bridge sensitivity Gain adjustment Pot fine adj Zero adjustment Pot fine adj Output load Bandwidth Zero temperature stability Span temperature stability Linearity Operating temperature range Humidit FS Full scale t set by calibration resistor 24V minimum supply sink mode Configuration sink or source mode Connections Solder pads 4 strain gauge 3 or 4 for power amp signal Environmental Approvals EMC Emissions EN 50 081 1 1992 Light industrial EMC Emissions EN 50 081 2 1992 Heavy industrial EMC Immunity EN 50 082 1 1992 Light industrial RF Fields Test 100 ppm of reading over 30 to 5S0OMHz EN 50 082 2 1992 Heavy industrial RF Fields Test 500 ppm of reading over 30 to SOOMHz Low Directive IEC 1010 EN 61010 14 Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 Other Man
14. ormeters and P2 for Span and Zao respecte A Wheatstone Bridge configuration utilizing four active elements or Strain Gauges The algebraic difference between the minimum output and maximum output Gain Gain is otherwise identified as SPAN It relates to the proportional output to the sensor input Calibration of the ICA is determined by setting the Gain Span and md Offset Zero The amount of amplification used in an electrical circuit Ground Earth The electrical neutral line having the same potential as the surrounding earth Linearity The closeness of a calibration curve to a specified straight line Linearity is expressed as the maximum deviation of any calibration point on a specified ie straight line during any one calibration cycle Load The electrical demand of a process expressed as power watts current amps ee or resistance ohms associated external circuitry Load Cell The load cell is one of a series of STRAIN GAUGE sensors that the ICA input is ene designed to accept Torque Sensor Pressure amp temperature transducers A condition such as balance which results in a minimum absolute value of output Offset Offset is otherwise identified as ZERO Calibration of the ICA is determined by setting the Offset Zero and Gain Span Potentiometer Two potentiometers variable resistors are used in the ICA for fine calibration Pressure The Pressure Transducer is one of a series of Strain Gauge sensors that the Transduc
15. re the package is secure and protected Figure 2 1 Dimensions The module is designed to fit in the strain gauge pocket Use the 2 5mm hole to secure the unit if required Take care soldering cables to the pads Use a temperature controlled soldering iron set to a maximum 330 C for no longer than 2 seconds per pad Excessive heat or increased soldering time may result in damage to the PCB If changing resistor R do so at a workbench and not on site Check the relevant details for model ICA4 ensure the module matches the instructions The ICA4 solder pads are as shown 4 pads for the strain gauge 2 pads for linking the required mode 2 pads are for power supply 1 pad for earth link to chassis 2 pads for the output Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 3 Power Connections The power supply for the ICA4 is 24V dc within the limits of 13 to 28 V Figure 2 2 Connection Details for Source Current ICA4 SOURCE MODE CONNECTION Supply Strain Out Output R Gauge Out e Load cell chassis N B Output is connected internally to the Supply Com For optimum EMC performance connect to Load Cell chassis Figure 2 3 Connections for Sink Current SINK MODE CONNECTION 8 Out Supply Strain Out LOAD Gauge S Out N Output e Load cell chassis N B Output is connected x ve end of load can be connected internally to the Supply to separate 5
16. sseneeeeeenaes 8 Chapter 5 TroubleShooting ecccccseeeeceseeeeeeeseenseeeseeseeeeeeeseceseeeseceseeeseseeeeeseseseaesesesnensnenseeanes 9 Chapter 6 Product Care ter Degsgeke ge e ee SEENEN eege 11 Chapter T GIOSSAIY E 12 Chapter 8 Specifications for ICA4 Load Cell Amplifiers c cccccessesseeeeeeeeeeeeeeeseenes 14 Table 8 1 Output From the ICA4 4 20MA cece ceccecceceeeeeeeceeeeeeeeeeetetcaaeeaeeeeeeeeetennaees 14 Environmental Approvals ccceccececeeeeeeeeeceeeeeeeeeecceacaeeeeeeesesecaeaeeeeeeesetennueeeeeeeeeeeeteees 14 Other Mantracourt Products ut kEEKSENAEEASENEEEE K EN cecseesubncsctentessasseldeecect cxesseseGneecetivetenasstsneeee 15 Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 1 Chapter 1 Introduction to The ICA Range Figure 1 1 Block Diagram POWER d SUPPLY AMPLIFIER INPUT CG S gt OUTPUT Load Cells 0 1 10V Strain Gauges 0 1 5V Torque Transducers 10V Pressure Transducers 4 20mA The ICA is a Strain Gauge Amplifier converting a strain gauge input to a Volt or mA output otherwise known as a Signal Conditioner The ICA provides a wide range of signal conditioning for Strain Gauges Load Cells Pressure and Torque Transducers Offered in 4 versions e ICA1 3 wire 0 1 to 10 volts e ICA2 3 wire 0 1 to 5 volts e ICA3 4 wire 10 volts e ICA4 3 wire 4 to 20 mA This manual only deals with Version ICA4 separate manuals ex
17. stallation This is when an output is present but higher or lower in span or zero than expected a Check the installation for problems and repair where necessary b Poor termination c High resistance on cable leads d Low insulation impedance e Proximity to High Voltage Equipment Transformers Contactors Motors etc Noisy Environment a Check if the source can be found and remove noise b Check the cable screening and ensure it is correctly installed and terminated 5 Calibration This section assumes that the unit is providing an output that is not stuck at top or bottom of the scale See paragraphs 1 3 if this is the case Ensure you are connected to the correct sensor and not to another adjacent unit Ensure you have the correct calibration data from the sensor manufacturer This must include a certified table with offset zero and linearity Ensure you have the calibration set up correctly installed i e mV source and output as required Mantracourt Electronics Limited ICA4 User Manual Issue 1 1 9 Ensure the temperature and other environmental parameters are within specification and where necessary taken into account when calibrating should such parameters have an effect on the calibration 6 Fine Span Gain and Zero Offset Adjustment Problems If the adjustment cannot reach the maximum output desired then check the tare is not too high If the potentiometer does not alter the output the unit must be repaire
18. tracourt Products www mantracourt co uk Signal Conditioning SGA RCA15 STRAIN GAUGE AMPLIFIER RACK MOUNTED INTELLIGENT Connect up to 4 strain gauges STRAIN GAUGE AMPLIFIER Proportional mA and or Voltage output Complete MULTI CHANNEL system for Strain Simple DIL switch configuration gauges Set Sensitivity and Low pass filter and Relay and or serial outputs per channel output Multidrop serial link Simple Reliable Rugged 19 Eurorack x 3U high Capability similar to the ADW 15 High integrity compact Data acquisition unit LCA ADW15 Mantraweigh IN LINE INTELLIGENT 72 mm DIN Module Display amp Controller STRAIN GAUGE AMPLIFIER 10 mm LED Display Configurable 2 Set Points Sensitivity from 0 5 mV to 200 mV V 4 to 20 mA AND 0 to 10 V isolated outputs 10 V 150 mA Excitation RS 232 485 Communications port Isolated 1 0100mSec sample rate On Board easy to use Programmer Set Point Relays Auto tare Auto calibrate and much more 4 to 20 mA Output Programmable via keypad FIELDBUS CONNECTIVITY IN TWO EXCELLENT PACKAGES DSC The Digital Strain Card D Cell The in cell Digital Strain Puck Mount this package adjacent to the strain Mount this package directly into the strain gauge gauge pocket Plug in and go sensor High accuracy Integrate the electronics with the load cell e A quantum leap in the quality of measurement remove the cost space and bother of additional electronics and have a direct output provided in REAL ENG
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