LaMotte DC1100 User Manual

MODEL DC1100

Instruction Manual

Helping People Solve Analytical Challenges

800-344-3100 • 410-778-3100 (Outside U.S.A.) • Fax: [phone]

LaMOTTE COMPANY

PO Box 329 • Chestertown • Maryland • 21620 • USA

Visit us on the web at www.lamotte.com

®

AN INTRODUCTION TO COLORIMETRIC ANALYSIS

Most test substances in water are colorless and undetectable to the human eye.
In order to test for their presence, we must find a way to “see” them. The
LaMotte colorimeter 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.

A colorimeter 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. Little difference could be measured between white light
before it passes through a colored sample versus after it passes through. 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. A colorimeter
passes a white light beam through an optical filter which transmits only one
particular color or band of wavelengths of light to the photodetector where it is
measured. The difference in the amount of colored light transmitted by a
colorless sample (blank) and the amount of colored light transmitted by a
colored sample is a measurement of the amount of colored light absorbed by the
sample. In most colorimetric tests the amount of colored light absorbed is
directly proportional to the concentration of the test factor producing the color
and the path length through the sample. However, for some tests the amount of
colored light absorbed is inversely proportional to the concentration.

The choice of the correct optical filter and therefore the correct color or
wavelength of light is important. It is interesting to note that the filter that
gives the most sensitive calibration for your 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 green filter is used since a
pinkish-red solution absorbs mostly green light.

2

THE MODEL DC1100 COLORIMETER

The DC1100 colorimeter has been specially calibrated to read the test result
directly in parts per million (ppm) of a desired substance (i.e. ppm chlorine,
ppm phosphate). The sensitivity of the DC1100’s response has been maximized
by selecting a specific, complimentary light source for each test. The light
chosen is absorbed by the color of the test solution. For example, a green light
is used for reactions that will produce a red sample. Since green light is
absorbed in a red solution, the detector can respond to minute variations in the
intensity of the transmitted light.

MODEL DC1100 SINGLE-PARAMETER TEST KITS

The DC1100 can be supplied with reagents for a variety of tests, including
wastewater monitoring, industrial process control, boiler and cooling water
testing, pool and spa water testing, public health inspection, environmental
studies, aquaculture, hydroponics, and other general water analysis applications.
The meter, reagents, glassware and accessories are packaged in foam in a
compact carrying case for easy transportation and field use.

SPECIFICATIONS

MODEL:

INSTRUMENT TYPE:

DC1100
Single wavelength, direct reading colorimeter
Readout: 3

1

digit LCD

2

Reading Stability: Within 1% of final value
within 5 seconds

PHOTOMETRIC DATA:

Source: Light emitting diode
Detector: Filtered photo-diode

Configuration: Round 21 mm diameter sample

tubes (flat bottom) indexed in chamber

CONTROLS:

ON/OFF
SET BLANK

POWER REQUIREMENTS:

Battery Operated: Field replaceable NEDA
#1604A, 9 volt

Line Operation: 120/220V, 50/60Hz, 2VA
with optional adapter

METER HOUSING:

Dimensions: (HxWxD),150mmx80mm

3

3

“x1

x 45 mm, 6" x

4

”

4

3

GENERAL OPERATING INSTRUCTIONS

K

1. Fill the water sample bottle (0688) with the sample water.

2. Fill colorimeter tube (0967) to 10 mL line with water from sample bottle.

The bottom of the curved surface, the meniscus, should rest on the top of
the line.

3. Cap the colorimeter tube and insert into the DC1100 colorimeter chamber.

NOTE: Dry all colorimeter tubes with a tissue before inserting into the

chamber. Also be sure that there are no scratches on the tubes. Keep
the chamber clean and dry at all times.

4. Press the “ON/OFF” button and adjust the SET BLANK knob until the

display reads 0. Once this adjustment has been made, do not move the
SET BLANK knob for the remainder off the test.

Low Battery
Indicator

ON/OFF
Button

NOTE:

The location of the decimal point may vary for different meters.

~

BA T

SET BLAN
Knob

Sample
Chamber

4

5. For best results, use the same tube that was used to adjust the blank for all

measurements. If the test you are performing requires a wait of more than
thirty seconds, turning the meter off will extend battery life.

6. Follow individual test instructions to add reagents to the tube.

7. Cap the treated sample tube, making sure the tube is clean and dry, then

insert the tube into the chamber.

8. Press the “ON/OFF” button if the meter has been turned off. Record

reading directly from the display.

TEST SAMPLE DILUTIONS AND VOLUMETRIC MEASUREMENTS

If the indicated reading is higher than the maximum concentration specified on
the reagent specifications, a dilution should be done to ensure accuracy. In rare
cases of extremely high concentrations, the display may indicate an over-range
condition: the left digit will be a “1,” the other digits will remain blank. The
sample must then be diluted with demineralized water and the test repeated to
bring the concentration within a range that can be accurately measured by the
meter. The reading is then multiplied by the appropriate dilution factor to
obtain the test result.

EXAMPLE:

Measure 5 mL of the original sample into a graduated cylinder. Dilute to 10 mL
with distilled or demineralized water. The sample has now been diluted by half,
and the test results are multiplied by 2.

The following dilution table shows the amount of original sample to be diluted,
the amount of distilled or demineralized water required, and the dilution factor.
Since the tests are based on a 10 mL sample, the dilutions must be measured
accurately to assure reliable results.

Distilled Water to Bring

Size of Sample

Volume to 10 mL Multiplication Factor

10 mL 0 mL 1

5mL 5mL 2

2.5 mL 7.5 mL 4

1 mL 9 mL 10

0.5 mL 9.5 mL 20

NOTE: When measuring small sample sizes, use graduated cylinders or pipets,

and measure the final dilution in a graduated cylinder. Pipet the
sample water into the graduated cylinder, then fill the cylinder to the
10 mL line with distilled or demineralized water.

5

REAGENT BLANK

For greater accuracy, the test procedure should be run on a 10 mL sample of
deionized water, known as the reagent blank. This procedure will compensate
for color or turbidity that the reagents may produce. Subtract this result from
the test result to receive final reading.

REPLACING THE BATTERY

When the battery indicator appears on the display, the battery should be
replaced.

1. Turn meter over and remove four screws from the meter base.

2. Remove old battery and insert new battery. The DC1100 uses a Type

1604A 9 volt Alkaline battery.

CONNECTING THE AC ADAPTER

To connect meter to a power source, plug the connector of the AC adapter into
the small hole at the back of the meter. Plug large end into an electrical outlet
(120V, 60Hz).

WARRANTY INFORMATION

REPAIRS

If it is necessary to return the instrument for repair, contact LaMotte Company
at 1-800-344-3100 for a return authorization number.

INSTRUMENT GUARANTEE

This instrument is guaranteed to be free of defects in material and workmanship
for one year from date of original purchase. If, in that time, it is found to be
defective, it will be repaired without charge, except for transportation expenses.
This guarantee does not cover the batteries.

This guarantee is void under the following circumstances:

•

operator’s negligence

•

improper application

•

unauthorized servicing

LIMITS OF LIABILITY

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

PACKAGING AND DELIVERY

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

6

TROUBLE SHOOTING GUIDE

PROBLEM CHECK ACTION

Meter won’t
come on

^ AC Adapter? See pg. 6 of manual.

^ AC Wall Outlet? Verify power source.

^ Contact LaMotte for

^

Comes on, but
readings drift

^ Are there suspended solids

^ Do reading drift up scale? Bring samples to room temperature.

^ Readings drift down scale

Battery? Replace, see pg. 6 of manual.

return authorization.

Are instrument grade
reagents being used?

in sample?

with cold sample?

Return to LaMotte for repair.

Obtain instrument grade reagents.

Filter both blank and sample
(after reaction).
NOTE: Do not use filtered blank for
sample reaction.

Check for sample tube fogging, let
sample equilibrate to room temperature.

Suspect
Calibration

^ Are instrument grade

^ How old are the reagents? Contact LaMotte to verify age.

^ Check calibration with

^ Is class “A” volumetric

Will meter blank? (zero) If no, see next page.

reagents being used?

standards?

glassware being used to
make up the standards?

Obtain instrument grade reagents.

How old is the standard?

If not, obtain and see Standard
Methods.

7

TROUBLE SHOOTING GUIDE (continued)

PROBLEM CHECK ACTION

Suspect
Calibration

^ Verify with another

^ Contact LaMotte for

^

Meter won’t zero Sample tubes free of dirt

^ Sample tubes clean? Clean tubes often with soap and a test

^ Possible internal meter

^ LED contaminated with

^ High suspended solids in

Verify standard with
alternate test method?

meter?

return authorization.

& scratches?

components subjected to
moisture?

dirt and deposits?

sample blank?

Run alternate test on standard.

Check other meter calibrations.

Return for Calibration check.

Check & replace if necessary.

tube brush. Do not leave reacted
samples in tubes, staining may occur.

Always dry tubes before inserting.
Examine tube chamber for visible
moisture or chemical stains. If yes,
remove 4 screws from back, split case &
dry with hair dryer under low heat (10 ­15 min).

Clean square LED and Photodetector
w/cotton swab & small amount of
alcohol.

Filter with coffee filter, or similar, to
remove most solids. (Be sure to filter
reacted samples as well)
NOTE: Do not use filtered blank for
sample reaction.

Meter read 1 ­w/o samples in
chamber

Meter read 1 ­only when samples
in chamber

Meter over range? Contact LaMotte for return

authorization & return.

Meter over range? Extremely high concentration, dilute

sample to see if 1 - condition returns to
normal condition.

12/95