LaMotte SMART3 Colorimeter User Manual

OPERATOR’S MANUAL

v3.0 and higher • Printed 2.11

2000-01-MN

CONTENTS
 GENERAL INFORMATION
Packaging & Delivery ....................................................................................	4
General Precautions ......................................................................................	4
Safety Precautions ........................................................................................	4
Limits of Liability ............................................................................................	5
Warranty .........................................................................................................	5
Specifications ................................................................................................	6
Statistical and Technical Definitions
Related to Product Specifications................................................................	6
Contents and Accessories .............................................................................	8
EPA Compliance ............................................................................................	8
CE Compliance ..............................................................................................	8
 CHEMICAL TESTING
Water Sampling for Chemical Analysis .........................................................	9
Filtration .......................................................................................................	10
An Introduction to Colorimetric Analysis & Spectroscopy .........................	11
Reagent Blank .............................................................................................	12
Spectrophotometer Tubes ...........................................................................	12
Selecting an Appropriate Wavelength ........................................................	12
Calibration Curves .......................................................................................	13
Preparing Dilute Standard Solutions............................................................	15
Standard Additions ......................................................................................	15
Sample Dilution Techniques & Volumetric Measurements .........................	16
Interferences ................................................................................................	17
Stray Light Interference ...............................................................................	17
 OPERATION OF THE SMART SPECTRO
SPECTROPHOTOMETER
Overview ......................................................................................................	18
Power Supply ...............................................................................................	18
Components ................................................................................................	19
Quick Start ...................................................................................................	20
 GENERAL OPERATING PROCEDURES

The Keypad .................................................................................................	22
Sample Holders............................................................................................	22
The Display & the Menus ............................................................................	23

 CALIBRATION

Calibrate Wavelength ..................................................................................	24
 PROGRAMMED TESTS
Introduction .................................................................................................	25
Sequences of Tests .....................................................................................	26
General Testing Procedures ........................................................................	27
Testing with the Programmed Tests ............................................................	27
 SETUP & EDIT SEQUENCES & USER TESTS
Edit a Sequence ..........................................................................................	30
Adding or Deleting Tests .............................................................................	31
Edit User Tests .............................................................................................	35
Naming the Test .................................................................................	37
Selecting the Wavelength ..................................................................	39
Entering a New Calibration ................................................................	40
Selecting the Numerical Format of the Result ..................................	43
 MEASURING IN THE %T/ABS MODE
44
 PC LINK
Output ..........................................................................................................	46
Computer Connection .................................................................................	46
 EDIT CLOCK	47
 ENERGY MODE	48
 STORE METHOD	49
 TEST MODE	50
 BATTERY OPERATION
Charging the Batteries ................................................................................	51
Running the SMART Spectro Using Batteries ............................................	51
 MAINTENANCE
Cleaning ......................................................................................................	52
Light Bulb ....................................................................................................	52
Clock Battery ...............................................................................................	52
Meter Disposal..............................................................................................	53
 TROUBLESHOOTING GUIDE
Error Messages ...........................................................................................	54
Helpful Hints ................................................................................................	55

SMART SPECTRO TEST PROCEDURES

APPENDIX

GENERAL INFORMATION

 PACKAGING & DELIVERY

Experienced packaging personnel at LaMotte Company assure adequate protection against normal hazards encountered in transportation of shipments. After the product leaves the manufacturer, all responsibility for its safe delivery is assured by the transportation company. Damage claims must be filed immediately with the transportation company to receive compensation for damaged goods.

Should it be necessary to return the instrument for repair or servicing, pack instrument carefully in suitable container with adequate packing material. A return authorization number must be obtained from LaMotte Company by calling 1-800-344-3100. Attach a letter with the authorization number to the shipping carton which describes the kind of trouble experienced. This valuable information will enable the service department to make the required repairs more efficiently.

 GENERAL PRECAUTIONS

Before attempting to set up or operate this instrument it is important to read the instruction manual. Failure to do so could result in personal injury or damage to the equipment.

The SMART Spectro should not be stored or used in a wet or corrosive environment. Care should be taken to prevent water or reagent chemicals from wet spectrophotometer tubes from entering the SMART Spectro chamber.

NEVER PUT WET TUBES IN SPECTROPHOTOMETER.

 SAFETY PRECAUTIONS

Read the labels on all LaMotte reagent containers prior to use. Some containers include precautionary notices and first aid information. Certain reagents are considered hazardous substances and are designated with a * in the instruction manual. Material Safety Data Sheets (MSDS) available at www.lamotte.com. Read the accompanying MSDS before using these reagents. Additional emergency information for all LaMotte reagents is available 24 hours a day from the Poison Control Center listed in the front of the phone book or by contacting the 24 hour emergency line for ChemTel 1-800-255-3924 (USA, Canada,

Puerto Rico); locations outside the North American continent 813-248-0585. Be prepared to supply the name and four-digit LaMotte code number found on the container label or at the top of the MSDS or in the contents list for the test procedure. LaMotte reagents are registered with a computerized poison control information system available to all local poison control centers.

Keep equipment and reagent chemicals out of the reach of young children.

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 LIMITS OF LIABILITY

Under no circumstances shall LaMotte Company be liable for loss of life, property, profits, or other damages incurred through the use or misuse of their products.

 WARRANTY

LaMotte Company warrants this instrument to be free of defects in parts and workmanship for 2 years from the date of shipment. If it should become necessary to return the instrument for service during or beyond the warranty period, contact our Technical Service Department at 1-800-344-3100 for a

return authorization number or visit www.lamotte.com for troubleshooting help. The sender is responsible for shipping charges, freight, insurance and proper packaging to prevent damage in transit. This warranty does not apply to defects resulting from action of the user such as misuse, improper wiring, operation outside of specification, improper maintenance or repair, or unauthorized modification. LaMotte Company specifically disclaims any implied warranties or merchantability or fitness for a specific purpose and will not be liable for any direct, indirect, incidental or consequential damages. LaMotte Company’s total liability is limited to repair or replacement of the product. The warranty set forth

above is inclusive and no other warranty, whether written or oral, is expressed or implied.

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 SPECIFICATIONS

INSTRUMENT TYPE: Single beam spectrophotometer

Readout	5 line, 18 character per line LCD
Wavelengths	350-1000 nm
Wavelength Accuracy	± 2 nm
Wavelenth Resolution	1 nm
Wavelength Bandwidth	5 nm (max)
Photometric Range	0-125%T, –0.1-2.5A
Photometric Accuracy	± 0.005A
Photometric Stray Light	<0.5%T
Dispersive Device	1200 Lines/mm ruled grating
Sample Chamber	Accepts 25 mm diameter flat-bottomed test tubes,
	10 mm square cuvettes, 16 mm COD test tubes
Source Lamp	Quartz halogen
Modes	%/T, ABS, pre-programmed tests
Pre-Programmed Tests	YES, with automatic wavelength selection
Languages	English or Chinese
User Defined Tests	Up to 25 user tests can be input
RS232 Port	8 pin mDIN
Power Requirements	Battery Operation (optional): Ni-Metal Hydride
	battery pack Line Operation: 110/220V, 50/60 Hz
Dimensions	36 cm (wide) x 28 cm (deep) x 17 cm (tall)
Weight	10.3 lbs, 4.65 kgs

STATISTICAL AND TECHNICAL DEFINITIONS RELATED TO PRODUCT SPECIFICATIONS

Method Detection Limit (MDL): “The method detection limit (MDL) is defined as the minimum concentration of a substance that can be measured and reported with 99% confidence that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte.”1 Note that, “As Dr. William Horwitz once stated, ‘In almost all cases when dealing with a limit of detection or limit of determination, the primary purpose of determining that limit is to stay away from it.’”2

1.CFR 40, part 136, appendix B

2.Statistics in Analytical Chemistry: Part 7 – A Review, D. Coleman and L Vanatta, American Laboratory, Sept 2003, P. 31.

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Precision: Precision is the numerical agreement between two or more measurements.3 The precision can be reported as a range for a measurement (difference between the min and max). It can also be reported as the standard deviation or the relative standard deviation. It is a measure of how close together the measurements are, not how close they are to the correct or true value. The precision can be very good and the accuracy very bad. This is a useful measure of the performance of a test method.

3.Skoog, D.A., West, D. M., Fundamental of Analytical Chemistry, 2nd ed., Holt Rinehart and Winston, Inc, 1969, p. 26.

Accuracy: Accuracy is the nearness of a measurement to the accepted or true value.4 The accuracy can be expressed as a range, about the true value, in which a measurement occurs (i.e. ±0.5 ppm). It can also be expressed as the % recovery of a know amount of analyte in a determination of the analyte (i.e. 103.5 %). This is a useful measure and what most customers are interested in when they want to know about the performance of a test method.

4.Skoog D.A., West D. M., Fundamental of Analytical Chemistry, 2nd ed., Holt Rinehart and Winston, Inc, 1969, p. 26.

Resolution: Resolution is the smallest discernible difference between any two measurements that can be made.5 For meters this is usually how many decimal places are displayed. (i.e. 0.01). For titrations and various comparators it is the smallest interval the device is calibrated or marked to (i.e. 1 drop = 10 ppm, 0.2 ppm for a DRT, or ±half a unit difference for an octaslide or color chart). Note that the resolution many change with concentration or range. In some cases the resolution may be less than the smallest interval, if it is possible to make a reading that falls between calibration marks. This is often done with various comparators. One caveat is, that resolution has very little relationship to accuracy or precision. The resolution will always be less than the accuracy or precision but it is not a statistical measure of how well a method of analysis works. The resolution can be very very good and the accuracy and precision can be very, very bad! This is not a useful measure of the performance of a test method.

5.Statistics in Analytical Chemistry: Part 7 – A Review, D. Coleman and L Vanatta, American Laboratory, Sept 2003, P. 34.

Sensitivity: Sensitivity is the resolution based on how this term is used in LaMotte catalogs. This term is not listed in any of the references. Sometimes it is used for detection limit. It is a confusing term and should be avoided.

Repeatability: Repeatability is the within-run precision.6 A run is a single data set, from set up to clean up. Generally, one run occurs on one day. However, for meter calibrations, a single calibration is considered a single run or data set, even though it may take 2 or 3 days.

6.Jeffery G. H., Basset J., Mendham J., Denney R. C., Vogel’s Textbook of Quantitative Chemical Analysis, 5th ed., Longman Scientific & Technical, 1989, p. 130.

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Reproducibility: Reproducibility is the between-run precision.7

7.Jeffery G. H., Basset J., Mendham J., Denney R. C., Vogel’s Textbook of Quantitative Chemical Analysis, 5th ed., Longman Scientific & Technical, 1989, p. 130.

 CONTENTS AND ACCESSORIES

CONTENTS

SMART Spectro Spectrophotometer	Battery Charger
Test Tubes, with Caps	Power Supply, 110/220V
Sample Cell Holder, Universal	SMART Spectro Quick Start Guide
Sample Cell Holder, 10 mm Square	SMART Spectro Manual
Power Cable

NOTE: The battery pack is not included and must be purchased separately. An empty slot is located in the original foam for the battery pack.

 ACCESSORIES

Battery Pack with Holder (rechargeable)	Code 2000-BP
Carrying Case	Code 2000-CS
SMARTLink 2 Software with Cable	Code 1912-CD
(compact disk)

 EPA COMPLIANCE

The SMART Spectro is an EPA-Accepted instrument. EPA-Accepted means that the instrument meets the requirements for instrumentation as found in test procedures that are approved for the National Primary Drinking Water Regulations (NPDWR) or National Pollutant Discharge Elimination System (NPDES) compliance monitoring programs. EPA-Accepted instruments may be used with approved test procedures without additional approval.

 CE COMPLIANCE

The SMART Spectrophotometer has been independently tested and has earned the European CE Mark of Compliance for electromagnetic compatibility and safety. To view the Declaration of Conformity go to www.lamotte.com.

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CHEMICAL TESTING

 WATER SAMPLING FOR CHEMICAL ANALYSIS

Taking Representative Samples

The underlying factor to be considered for any type of water sampling is whether or not the sample is truly representative of the source. To properly collect a representative sample:

•Sample as frequently as possible.

•Collect a large sample or at least enough to conduct whatever tests are necessary.

•Make a composite sample for the same sampling area.

•Handle the sample in such a way as to prevent deterioration or contamination before the analysis is performed.

•Perform analysis for dissolved gases such as dissolved oxygen, carbon dioxide, and hydrogen sulfide immediately at the site of sampling. These factors, as well as samples for pH testing, cannot be stored for later examination.

•Make a list of conditions or observations which may affect the sample. Other considerations for taking representative samples are dependent upon the source of the sample. Taking samples from surface waters involves different considerations than taking samples from impounded and sub-surface waters.

Sampling of Open Water Systems

Surface waters, such as those found in streams and rivers, are usually well mixed. The sample should be taken downstream from any tributary, industrial or sewage pollution source. For comparison purposes samples may be taken upstream and at the source of the pollution.

In ponds, lakes, and reservoirs with restricted flow, it is necessary to collect a number of samples in a cross section of the body of water, and where possible composite samples should be made to ensure representative samples.

To collect samples from surface waters, select a suitable plastic container with a tight fitting screw cap. Rinse the container several times with the sample

to be tested, then immerse the container below the surface until it is filled to overflowing and replace the cap. If the sample is not to be tested immediately, pour a small part of the sample out and reseal. This will allow for any expansion. Any condition which might affect the sample should be listed.

Sub-surface sampling is required to obtain a vertical profile of streams, lakes, ponds, and reservoirs at specific depths. This type of sampling requires more sophisticated sampling equipment.

For dissolved oxygen studies, or for tests requiring small sample sizes, a Water

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Sampler (LaMotte Code 1060) will serve as a sub-surface or in-depth sampler. This weighted device is lowered to the sampling depth and allowed to rest at this depth for a few minutes. The water percolates into the sample chamber displacing the air which bubbles to the surface. When the bubbles cease to rise, the device has flushed itself approximately five times and it may be raised to the surface for examination. The inner chamber of the sampling device is lifted out and portions of the water sample are carefully dispensed for subsequent chemical analysis.

A Snap-Plunger Water Sampler (LaMotte Code 1077) is another “in-depth” sampling device which is designed to collect large samples which can be used for a multitude of tests. Basically, this collection apparatus is a hollow cylinder with a spring loaded plunger attached to each end. The device is cocked above the surface of the water and lowered to the desired depth. A weighted messenger is sent down the calibrated line to trip the closing mechanism

and the plungers seal the sample from mixing with intermediate layers as it is brought to the surface. A special drain outlet is provided to draw off samples for chemical analysis.

Sampling of Closed System

To obtain representative samples from confined water systems, such as pipe lines, tanks, vats, filters, water softeners, evaporators and condensers,

different considerations are required because of chemical changes which occur between the inlet and outlet water. One must have a basic understanding of the type of chemical changes which occur for the type of equipment used. Also, consideration should be given to the rate of passage and retaining time for the process water.

Temperature changes play an important part in deciding exactly what test should be performed. Process water should be allowed to come to room temperature, 20–25°C, before conducting any tests.

When drawing off samples from an outlet pipe such as a tap, allow sample to run for several minutes, rinsing the container several times before taking the final sample. Avoid splashing and introduction of any contaminating material.

 FILTRATION

When testing natural waters that contain significant turbidity due to suspended solids and algae, filtration is an option. Reagent systems, whether EPA, Standard Methods, LaMotte or any others, will generally only determine dissolved constituents. Both EPA and Standard Methods suggest filtration through a 0.45 micron filter membrane, to remove turbidity, for the determination of dissolved constituents.** To test for total constituents, organically bound and suspended or colloidal materials, a rigorous high temperature acid digestion is necessary.

**LaMotte offers a filtering apparatus: syringe assembly (Code 1050) and membrane filters, 0.45 micron, (Code 1103).

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AN INTRODUCTION TO COLORIMETRIC ANALYSIS & SPECTROSCOPY

Most test substances in water are colorless and undetectable to the human eye. To test for their presence we must find a way to “see” them. The LaMotte SMART Spectro can be used to measure any test substance that is itself colored or can be reacted to produce a color. In fact a simple definition of colorimetry is “the measurement of color” and a colorimetric method is “any technique used to evaluate an unknown color in reference to known colors”. In a colorimetric chemical test the intensity of the color from the reaction must be proportional

to the concentration of the substance being tested. Some reactions have limitations or variances inherent to them that may give misleading results. Many such interferences are discussed with each particular test instruction. In the most basic colorimetric method the reacted test sample is visually compared to a known color standard. However, accurate and reproducible results are limited by the eyesight of the analyst, inconsistencies in the light sources, and the fading of color standards.

To avoid these sources of error, a colorimeter or spectrophotometer can be used to photoelectrically measure the amount of colored light absorbed by a colored sample in reference to a colorless sample (blank).

White light is made up of many different colors or wavelengths of light. A colored sample typically absorbs only one color or one band of wavelengths from the white light. Only a small difference would be measured between white light before it passes through a colored sample versus after it passes through a colored sample. The reason for this is that the one color absorbed by the sample is only a small portion of the total amount of light passing through the sample. However, if we could select only that one color or band of wavelengths of light to which the test sample is most sensitive, we would see a large difference between the light before it passes through the sample and after it passes through the sample.

The SMART Spectro uses a quartz halogen lamp as the source of white light. The white light passes through an entrance slit and is focused on a ruled grating consisting of 1200 lines/mm. The grating causes the light to be dispersed into various component wavelengths. The monochromator design allows the user to select which specific wavelength of interest will be passed through the exit slit and through the sample. The use of mirrors and additional filters prevents light of undesired wavelengths (overtones, stray light) from making it to the sample. A photodetector measures the amount of light which passes through the sample.

The difference in the amount of monochromatic light transmitted through a colorless sample (blank) and the amount of monochromatic light transmitted through a test sample is a measurement of the amount of monochromatic light absorbed by the sample. In most colorimetric tests the amount of monochromatic light absorbed is directly proportional to the concentration of the test factor producing the color and the path length through the sample. However, for a few tests the relationship is reversed and the amount of monochromatic light absorbed is inversely proportional to the concentration of the test factor.

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The choice of the correct wavelength for testing is important. It is interesting to note that the wavelength that gives the most sensitivity (lower detection limit) for a test factor is the complementary color of the test sample. For example the Nitrate-Nitrogen test produces a pink color proportional to the nitrate

concentration in the sample (the greater the nitrate concentration, the darker the pink color). A wavelength in the green region should be selected to analyze this sample since a pinkish-red solution absorbs mostly green light.

 REAGENT BLANK

Some tests will provide greater accuracy if a reagent blank is determined to compensate for any color or turbidity resulting from the reagents themselves. A reagent blank is performed by running the test procedure on 10 mL of demineralized or deionized water. Use sample water to SCAN BLANK. Insert the reacted reagent blank in the colorimeter chamber and select SCAN

SAMPLE. Note result of reagent blank. Perform the tests on the sample water as described. Subtract results of reagent blank from all subsequent test results.

NOTE: Some tests require a reagent blank to be used to SCAN BLANK.

 SPECTROPHOTOMETER TUBES

Spectrophotometer tubes which have been scratched through excessive use should be discarded and replaced with new ones. Dirty tubes should be cleaned on both the inside and outside. Fingerprints on the exterior of the tubes can cause excessive light scattering and result in errors. Handle the tubes carefully, making sure the bottom half of the tube is not handled.

LaMotte Company makes every effort to provide high quality spectrophoto-

meter tubes. However, wall thicknesses and diameter of tubes may still vary slightly. This may lead to slight variations in results (e.g. if a tube is turned while in the sample chamber, the reading will likely change slightly). To eliminate this error put the tubes into the sample chamber with the same orientation every time.

The tubes that are included with the spectrophotometer have an index mark to facilitate this. If possible, use the same tube to SCAN BLANK and SCAN SAMPLE.

 SELECTING AN APPROPRIATE WAVELENGTH

The most appropriate wavelength to use when creating a calibration curve is usually the one which gives the greatest change from the lowest reacted

standard concentration to the highest reacted standard concentration. However, the absorbance of the highest reacted standard concentration should never

be greater than 2.0 absorbance units. Scan the lowest and highest reacted standards at different wavelengths using the %T/ABS mode to find the wavelength which gives the greatest change in absorbance without exceeding 2.0 absorbance units. Use this wavelength to create a calibration curve.

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Below is a list of suggested wavelength ranges for the color of the reacted samples. Use these as a starting point.

Sample Color	Wavelength Range
Yellow	350-450
Yellow-Orange	450-490
Orange	490-510
Pink	510-570
Red	570-600
Green and Blue	600-750

 CALIBRATION CURVES

The SMART Spectro contains precalibrated tests for the LaMotte reagent systems. The first step in using a non-LaMotte reagent system with the SMART Spectro is to create a calibration curve for the reagent system. To create a calibration curve, prepare standard solutions of the test factor and use the reagent system to test the standard solutions with the SMART Spectro.

Plot the results (in ABS or %Transmittance) versus concentration to create a calibration curve. The calibration curve may then be used to identify the concentration of an unknown sample by testing the unknown, reading

Absorbance or %T, and finding the corresponding concentration from the curve. The linear range of the reagent system can be determined and this information can be used to input a User Test into the SMART Spectro (see EDIT USER TESTS, page 35).

PROCEDURE

1.Prepare 5 or 6 standard solutions of the factor being tested. The concentration of these standards should be evenly distributed throughout the range of the reagent system, and should include a 0 ppm standard (distilled water). For instance, the solutions could measure 0, 10%, 30%, 50%, 70%, and 90% of the system’s maximum range.

2.Turn on the SMART Spectro. Select the appropriate %T/ABS wavelength from the %T/ABS mode. Be sure to select the appropriate wavelength for the color produced by the reagent system.

3.Use the unreacted 0 ppm standard to standardize the spectrophotometer by using it to scan blank.

4.Following the individual reagent system instructions, react each standard solution including 0 ppm. Record the reading and the standard solution concentration on a chart. Readings can be recorded as percent transmittance (%T) or absorbance (A).

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5.Plot results on graph paper or computer using any available plotting program. If results are as %T versus concentration, semilog graph paper must be used. Plot the standard solution concentrations on the horizontal, linear axis, and the %T on the vertical, logarithmic axis. If results are as absorbance versus standard solution concentration, simple linear graph paper can be used. Plot the standard solution concentration on the horizontal axis, and the absorbance on the vertical axis.

6.After plotting the results, draw a line, or curve, of best fit through the plotted points. The best fit may not connect the points. There should be approximately an equal number of points above the curve as below the curve. Some reagent systems will produce a straight line, while others produce a curve. Many computer spreadsheet programs can produce the curve of best fit by regression analysis of the standard solution data.

A sample of each type of graph appears below:

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SMART Spectro Operator’s Manual 2.11

PREPARING DILUTE STANDARD SOLUTIONS

Standard solutions should be prepared to create a calibration curve. Standard solutions can be prepared by diluting a known concentrated standard by specified amounts. A chart or computer spreadsheet can be created to determine the proper dilutions. Use volumetric flasks and volumetric pipets for all dilutions.

1.In Column A – Record the maximum concentration of test as determined by the range and path length.

2.In Column B – Record the percent of the maximum concentration the standard solution will be.

3.In Column C – Calculate the final concentration of the diluted standard solutions by multiplying the maximum concentration (In Column A) by the % of maximum concentration divided by 100. (C = A x ).

4.In Column D – Record the final volume of the diluted sample (i.e. volume of volumetric flask).

5.In Column E – Record the concentration of the original standard.

6.In Column F – Calculate the milliliters of original standard required (C x D/E = F).

A sample chart appears below:

A	B	C=A x B/100	D	E	F=C x D/E
Maximum	% of Maximum	Final concentration	Volume of	Concentration	mL of
concentration	concentration	of Diluted Standard	Standard	of Original	Original Standard
of test				Standard	Required
10.0 ppm	90	9.0 ppm	100 mL	1000 ppm	0.90 mL
10.0 ppm	70	7.0 ppm	100 mL	1000 ppm	0.70 mL
10.0 ppm	50	5.0 ppm	100 mL	1000 ppm	0.50 mL
10.0 ppm	30	3.0 ppm	100 mL	1000 ppm	0.30 mL
10.0 ppm	10	1.0 ppm	100 mL	1000 ppm	0.10 mL
10.0 ppm	0	0 ppm	100 mL	1000 ppm	0 mL

 STANDARD ADDITIONS

A common method to check the accuracy and precision of a test is by standard additions. In this method a sample is tested to determine the concentration

of the test substance. A second sample is then “spiked” by the addition of a known quantity of the test substance. The second sample is then tested. The determined concentration of the spiked sample should equal the concentration of the first plus the amount added with the spike. The procedure can be repeated with larger and larger “spikes.” If the determined concentrations do not

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equal the concentration of the sample plus that added with the “spike”, then an interference may exist.

For example, a 10.0 mL water sample was determined to contain 0.3 ppm iron. To a second 10.0 mL sample, 0.1 mL of 50 ppm iron standard was added. The concentration of iron due to the “spike” was (0.10 mL x 50 ppm)/10.0 mL = 0.50 ppm. The concentration of iron determined in the spiked sample should be 0.3 + 0.5 = 0.8 ppm iron.

(Note: any error due to the increased volume from the “spike” is negligible).

LaMotte offers a line of calibration standards which can be used to generate calibration curves and perform standard additions.

SAMPLE DILUTION TECHNIQUES & VOLUMETRIC MEASUREMENTS

If a test result using the SMART gives an OUT OF RANGE message then the sample concentration could be over range or under range. If it is over range, the sample must be diluted. Then the test should be repeated on the diluted sample to obtain a reading which is in the concentration range for the test. (Note: This is not true for colorimetric determination of pH.)

Example:

Measure 5 mL of the water sample into a graduated cylinder. Add demineralized water until the cylinder is filled to the 10 mL line. The sample has been diluted by one-half, and the dilution factor is therefore 2. Perform the test procedure, then multiply the resulting concentration by 2 to obtain the test result.

The following table gives quick reference guidelines on dilutions of various proportions. All dilutions are based on a 10 mL volume, so several dilutions will require small volumes of the water sample. Graduated pipets should be used for all dilutions.

Size of Sample	Deionized Water to Bring	Multiplication Factor
	Volume to 10 mL
10 mL	0 mL	1
5 mL	5 mL	2
2.5 mL	7.5 mL	4
1 mL	9 mL	10
0.5 mL	0.5 mL	20

If the above glassware is not available, dilutions can be made with the spectrophotometer tube. Fill the tube to the 10 mL line with the sample then transfer it to another container. Add 10 mL volumes of demineralized water to the container and mix. Transfer back 10 mL of the diluted sample to the tube and follow the test procedure. Continue diluting and testing until a reading,

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which is in the concentration range for the test, is obtained. Be sure to multiply the concentration found by the dilution factor (the number of total 10 mL volumes used).

Example:

10 mL of sample is diluted with three 10 mL volumes of demineralized water; the dilution factor is four.

 INTERFERENCES

LaMotte reagent systems are designed to minimize most common interferences. Each individual test instruction discusses interferences unique to that test. Be aware of possible interferences in the water being tested.

The reagent systems also contain buffers to adjust the water sample to the ideal pH for the reaction. It is possible that the buffer capacity of the water sample may exceed the buffer capacity of the reagent system and the ideal pH will not be obtained. If this is suspected, measure the pH of a reacted distilled water reagent blank using a pH meter. This is the ideal pH for the test. Measure the pH of a reacted water sample using the pH meter. If the pH is significantly different from the ideal value, the pH of the sample should be adjusted before testing.

Chlorine interferences can be removed with the use of glycine. Very high levels of chloramines may interfere if the test result is not read immediately. Oxidized manganese interferes but can be removed with arsenite. Bromine and iodine interferes but can be removed with a thioacetamide blank correction.

Interferences due to high concentration of the substance being tested, can be overcome by sample dilution (see page 16).

 STRAY LIGHT INTERFERENCE

Normal indoor lighting causes no interference with the SMART. Always be sure the sample chamber lid is closed when scanning blanks or samples.

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OPERATION OF THE SMART SPECTRO

 OVERVIEW

The SMART Spectro is a portable, microprocessor controlled, direct reading, single beam spectrophotometer. It has a 5 line, 18 character liquid crystal display for alphabetical and numerical messages. The operation is controlled with the keypad through menu driven software in response to selections shown on the display.

The test library consists of over 80 LaMotte tests and 25 “User Tests”. The spectrophotometer is also capable of running %T/Absorbance tests over the entire wavelength range of 350 - 1000 nm. The LaMotte tests are precalibrated for LaMotte reagent systems. The spectrophotometer displays the results of these tests directly in units of concentration. The 25 “User Tests” may be used to enter additional calibrations. All of these tests may be arranged in any of 3 sequences. These sequences can be modified a limitless number of times to meet changing testing needs.

The optics feature a quartz halogen bulb as a light source with a minimum life expectancy of 1000 hours. The incident white light is dispersed into its

component wavelengths by a 1200 lines/mm ruled grating. The microprocessor controls the positioning of the grating, automatically positioning the grating to the correct wavelength for the test that has been selected. The monochromatic light is passed through the sample cell and is detected by a silicon photodiode.

The SMART Spectro is powered by an AC adapter that automatically recognizes the input voltage (110/220V) and converts it to the 12V needed to run the instrument. An optional battery pack is available for use where portability is important. To save power an automatic shut-off feature can be utilized (Energy Savings Mode).

A RS-232 serial port on the back of the spectrophotometer, and optional software, allows the spectrophotometer to be interfaced with a Winows-based personal computer for real time data acquisition and data storage. This port also allows an interface with a RS-232 serial printer.

Due to its portability, alternate power sources, and rugged construction, the SMART Spectro is ideal for lab and field use.

 POWER SOURCE

To use the SMART Spectro with an AC power supply:

1.Plug the Power Supply into the AC Adapter socket on the back of the SMART Spectro.

2.Connect the Power Cable to the Power Supply and an electrical outlet.

To use the Battery Pack, see page 51.

18	SMART Spectro Operator’s Manual 2.11

 COMPONENTS

Figure 1 shows a diagram of the SMART Spectro and the components.

AC Adapter

Socket

25mm Round Cell

in Universal

Adapter

Chamber

Make

Scroll Selections

Between

Choices

Turn Off
the Spectro	Exit
	Menus

SMART Spectro Operator’s Manual 2.11

RS232

Serial Port

10mm Square Cell in Adapter

Display

Scroll

Between

Choices

Turn On

the Spectro

Figure 1

19

QUICK START

1. Press ON. The LaMotte logo		MAIN MENU 12:00:01
screen will appear for about 2	*	CALIBRATE WL
seconds and the MAIN MENU will
appear.		PROGRAMMED TESTS
		%T/ABS
		PC LINK

2.Press or to scroll to PROGRAMMED TESTS.

MAIN MENU 12:00:01 CALIBRATE WL

*PROGRAMMED TESTS %T/ABS

PC LINK

3. Press *ENTER to select			PROGRAMMED TESTS
PROGRAMMED TESTS.		*	SEQUENCE 1
			SEQUENCE 2
			SEQUENCE 3
			ALL TESTS
4. Press	to scoll to ALL		PROGRAMMED TESTS
TESTS.			SEQUENCE 1
			SEQUENCE 2
			SEQUENCE 3
		*	ALL TESTS
5. Press *ENTER to select ALL			ALL TESTS
TESTS.		*	1 Alkalinity-UDV
			2 Aluminum
			3 Ammonia-N L F
			4 Ammonia-N L S

20	SMART Spectro Operator’s Manual 2.11

6. PresS	or	to scroll to the		ALL TESTS
desired test.				1 Alkalinity-UDV
			*	2 Aluminum
				3 Ammonia-N L F
				4 Ammonia-N L s

7.Press *ENTER to select the test.

2Aluminum

*SCAN BLANK

SCAN SAMPLE

END

535 NM

8.Insert the blank. Press *ENTER to scan the blank.

2 Aluminum

SCAN BLANK

*SCAN SAMPLE

END

535 NM

9.Insert the reacted sample. Press *ENTER to scan the sample. The result will be displayed.

2 Aluminum T = 16.5%T A = 0.7834A

C = 1.28 PPM PRINT PRESS ENTER

After obtaining test results, scroll with or , and make another selection with *ENTER. Press EXIT to escape to previous menu.

SMART Spectro Operator’s Manual 2.11

21

GENERAL OPERATING PROCEDURES

The operation of the SMART Spectro is controlled by a microprocessor. The microprocessor is programmed with menu driven software. A menu is a list of choices. This allows a selection of various tasks for the spectrophotometer to perform, such as, scan blank, scan sample, and edit test sequences. The keypad is used to make menu selections which are viewed in the display. There are eight selections accessible from the MAIN MENU - CALIBRATE WL, PROGRAMMED TESTS, %T/ABS, PC LINK, EDIT CLOCK, ENERGY MODE, STORE METHOD, and TEST MODE.

 THE KEYPAD

The keypad has 6 buttons which are used to perform specific tasks.

ON	This button is used to turn the spectrophotometer on.
	This button will cause the display to scroll up in a list of menu
	choices. It will move to the beginning of a list viewed in the display.
	It will auto scroll when held down.
	This button will cause the display to scroll down through a list of
	menu choices. It will move to the end of a list viewed in the display.
	It will auto scroll when held down.
*	This button is used to select the menu choice adjacent to the “*” in
ENTER	a menu viewed in the display.
EXIT	This button is an EXIT or ESCAPE button. When pressed, the
	display will EXIT from the current menu and go to the previous
	menu.
OFF	This button turns the spectrophotometer off.

 SAMPLE HOLDERS

The SMART Spectro Spectrophotometer is supplied with two removable sample cell holders. Each holder is secured in the chamber with a single screw. The square sample holder should be positioned so the arrow on the top is pointing toward the left. The square sample holder will hold 10 mm square cuvettes. The universal sample holder should be positioned with the V-channel toward the right side of the chamber. The universal sample holder will hold round tubes of varying diameters. When using the universal adapter, the tube should be placed between the white roller on the spring-loaded arm and the v-channel on the right-hand side of the adapter. Press the tube down on the white roller to retract the arm.

22	SMART Spectro Operator’s Manual 2.11

 THE DISPLAY & THE MENUS

The display allows menu selections to be viewed and chosen. These choices instruct the spectrophotometer to perform specific tasks. The menus are viewed in the display using a general format which is followed from one menu to the next. Each menu is a list of choices or selections.

There are five lines in the display. The top line in each menu is a title or pertinent instruction. The top line does not change unless a new menu is selected. The second line is used in two ways. One way is to display additional information if the top line is insufficient. The second line is also used to display menu choices. The three additional lines are also used for menu choices.

DISPLAY

TESTING MENU	Title or InstrucƟon
FIRST CHOICE
SECOND CHOICE	Menu Choice Window
THIRD CHOICE
AND ANOTHER
AND SO ON
END OF LIST

Think of the menu choices as a vertical list in the display which moves up or down each time an arrow button is pressed. This list or menu is viewed through a window, the menu choice window, in the display. Pushing the arrow buttons brings another portion of the menu into menu choice window. This is referred to as scrolling through the menu.

TESTING MENU		TESTING MENU		TESTING MENU
* FIRST CHOICE		SECOND CHOICE		ANOTHER
SECOND CHOICE		* ANOTHER		AND ANOTHER
ANOTHER		AND ANOTHER		* AND SO ON
AND ANOTHER		AND SO ON		END OF LIST
AND SO ON		END OF LIST
END OF LIST

An asterisk, “*”, will start in the far left position of the top line in the menu choice window. As the menu is scrolled through, different choices appear next to the “*”. The “*” in the display corresponds with the *ENTER button. Pushing the *ENTER button selects the menu choice which is adjacent to the “*” in the menu choice window.

As described previously, the EXIT button allows an exit or escape from the current menu and a return to the previous menu. This allows a rapid exit from an

SMART Spectro Operator’s Manual 2.11

23

inner menu to the MAIN MENU by repeatedly pushing the EXIT button. Pushing OFF at any time will turn the spectrophotometer off.

CALIBRATION

 CALIBRATE WAVELENGTH

The Calibrate Wavelength (CALIBRATE WL) mode is used to establish or re-establish the accuracy of the wavelength selection process. Normally, the Calibrate Wavelength procedure should be run after the SMART Spectro is turned ON and allowed to warm up for 15 minutes or if operating conditions (temperature, humidity, etc.) change significantly.

For field use, when operating with the battery, calibrate wavelength prior to going into the field using AC power. This will increase battery life in the field. Alternatively calibrate wavelength in the field immediately before testing. Turn Spectro on immediately before scanning blank. Calibrate wavelength just before scanning blank.

1. Press ON. The LaMotte logo			MAIN MENU	12:00:01
	screen will appear for about 2	*	CALIBRATE WL
	seconds and the MAIN MENU will
	appear.		PROGRAMMED TESTS
			%T/ABS
			PC LINK
2.	Press or to scroll to		MAIN MENU	12:00:01
	CALIBRATE WL.	*	CALIBRATE WL
			PROGRAMMED TESTS
			%T/ABS
			PC LINK
3.	Press *ENTER to select		MAIN MENU	12:00:01
	CALIBRATE WL.	*	CALIBRATE WL
			PROGRAMMED TESTS
			%T/ABS
			PC LINK

The Calibrate Wavelength procedure takes about 1-2 minutes to be completed. During the calibration, the Spectro will display two numbers at the bottom of the screen. The first number is fixed. The second number will change and can have a range of values. The microprocessor will move the grating in search of the position that gives a very specific maximum light intensity. The microprocessor

24	SMART Spectro Operator’s Manual 2.11

will then move the grating a precise predetermined amount from this position. This precise movement will cause the grating to be positioned at 546 nm every time. Once calibrated the wavelength displayed during testing is accurate to ±2 nm. When the wavelength calibration is complete the display will go back to the Main Menu.

PROGRAMMED TESTS

 INTRODUCTION

The PROGRAMMED TESTS mode is used to run all LaMotte pre-programmed tests and USER TESTS. This is also where USER TESTS and SEQUENCES are set-up and edited.

1. Press ON. The LaMotte logo			MAIN MENU	12:00:01
	screen will appear for about 2	*	CALIBRATE WL
	seconds and the MAIN MENU will
	appear.		PROGRAMMED TESTS
			%T/ABS
			PC LINK
2.	Press or to scroll to		MAIN MENU	12:00:01
	PROGRAMMED TESTS.		CALIBRATE WL
		*	PROGRAMMED TESTS
			%T/ABS
			PC LINK
3.	Press *ENTER to select		MAIN MENU	12:00:01
	PROGRAMMED TESTS. In	*	CALIBRATE WL
	the PROGRAMMED TESTS
	menu there are three alterable		PROGRAMMED TESTS
	sequences and one ALL TESTS		%T/ABS
	fixed sequence as well as the EDIT
			PC LINK
	function.

SMART Spectro Operator’s Manual 2.11

25

SEQUENCES OF TESTS

SEQUENCE 1, SEQUENCE 2, and SEQUENCE 3 are alterable sequences. They may be edited using the EDIT function mode. Any of the LaMotte preprogrammed tests or User Tests may be placed in these sequences in whatever testing order that is preferred. Some examples of typical sequences are given below.

	SEQUENCE 1		SEQUENCE 2			SEQUENCE 3
* 60 Molybdenum LR			* 1 Aluminum			* 3 Ammonia-N L F
79	Phosphate		35	Cyanide		32	Copper DDC
9 Bromine LR			41	Fluoride		64	Nitrate-N LR
76	pH TB		53	Iron Phen		67	Nitrite-N LR
15	Chlorine		55	Manganese L		74	pH CPR
86	Silica HI		64	Nitrate N LR		78	Phosphate L
45	Hydrazine		26	COD Low		85	Silica Lo
32	Copper DDC		77	Phenols		END OF LIST
51 Iron Bipyr			78	Phosphate L
END OF LIST			90	Sulfide LR

END OF LIST

NOTE: Sequences always end with END OF LIST to indicate that there are no more tests in the sequence.

These alterable sequences allow a series of tests to be setup that are run frequently. The order of the individual tests in the sequence is determined by the user. After running a test, press EXIT to escape back to the Sequence menu. Move the down to the next test listed and press *ENTER. Continue this pattern until the entire sequence has been completed.

ALL TESTS is a fixed sequence containing the LaMotte pre-programmed tests and User Tests.

Modification of the alterable sequence is accomplished through the EDIT function. This function is explained in detail in the section titled EDIT.

It should be noted that if a %T/ABS test is to be included in a sequence, the %T/ABS test must first be setup as a User Test (but no actual calibration needs to be performed, only select a name and wavelength).

Pressing the EXIT button while in a sequence menu will escape back to the

PROGRAMMED TESTS menu.

Pressing the OFF button at any time will turn the SMART Spectro off.

26	SMART Spectro Operator’s Manual 2.11

GENERAL TESTING PROCEDURES

The following are some step by step examples of how to run tests from the PROGRAMMED TESTS menu. These test procedures are designed to be used with LaMotte SMART Spectro reagent systems.

 TESTING WITH THE LaMOTTE PROGRAMMED TESTS

1. Press ON. The LaMotte logo			MAIN MENU	12:00:01
screen will appear for about 2		*	CALIBRATE WL
seconds and the MAIN MENU will
appear.			PROGRAMMED TESTS
			%T/ABS
			PC LINK
2. Press	or to scroll to		MAIN MENU	12:00:01
PROGRAMMED TESTS.			CALIBRATE WL
		*	PROGRAMMED TESTS
			%T/ABS
			PC LINK
3. Press *ENTER to select			PROGRAMMED TESTS
PROGRAMMED TESTS.		*	SEQUENCE 1
			SEQUENCE 2
			SEQUENCE 3
			ALL TESTS
4. Press	to scroll to ALL		PROGRAMMED TESTS
TESTS.			SEQUENCE 1
			SEQUENCE 2
			SEQUENCE 3
		*	ALL TESTS

SMART Spectro Operator’s Manual 2.11

27

5.	Press *ENTER to select ALL				ALL TESTS
	TESTS.			*	1 Alkalinity-UDV
					2 Aluminum
					3 Ammonia-N L F
					4 Ammonia-N L S
6.	Press	or	to scroll to the		ALL TESTS
	desired test.				1 Alkalinity-UDV
				*	2 Aluminum
					3 Ammonia-N L F
					4 Ammonia-N L S

7.Press *ENTER to select the test. The SMART Spectro is ready to scan. The proper wavelength has been selected.

2Aluminum

*SCAN BLANK

SCAN SAMPLE

END

535 NM

8.Insert the blank. Press *ENTER to scan the blank. The blank has been stored.

2 Aluminum

SCAN BLANK

*SCAN SAMPLE

END

535 NM

9.Insert the reacted sample. Press *ENTER to scan the sample. The result will be displayed.

2 Aluminum

T = 16.5%T

A = 0.7834A

C = 1.28 PPM

PRINT PRESS ENTER

28	SMART Spectro Operator’s Manual 2.11

10.Press *ENTER to print the result when connected to a printer or computer. To repeat the test, press EXIT to escape the test screen, then press *ENTER to scan the sample again. The last blank scanned is used to zero the spectrophotometer for repeat scans. A different blank can be used by pressing the button to scroll back to SCAN BLANK and then scanning another blank.

Press EXIT to escape back to the PROGRAMMED TESTS menu if no more samples are to be scanned for this test factor.

SMART Spectro Operator’s Manual 2.11

29

SETUP & EDIT SEQUENCES & USER TESTS

The EDIT menu allows any of the three alterable test sequences (SEQUENCE 1, SEQUENCE 2, and SEQUENCE 3) and any of the 25 User Tests in the

ALL TESTS fixed sequence to be edited. This feature allows a sequence or test which is used frequently to be set-up for easy access. The order of the sequence can be arranged to suit the needs of the user. Any combination, and any order of tests from ALL TESTS (including User Tests), may be placed into these sequences.

EDIT A SEQUENCE

1.Go to the PROGRAMMED TESTS menu. Press or to scroll to

EDIT.

PROGRAMMED TESTS SEQUENCE 1 SEQUENCE 2 SEQUENCE 3

*EDIT

2. Press *ENTER to select EDIT.		EDIT
	*	EDIT SEQUENCE 1
		EDIT SEQUENCE 2
		EDIT SEQUENCE 3
		EDIT USER TESTS

30	SMART Spectro Operator’s Manual 2.11