OfiTE 152-95 User manual

Calcimeter
Part No. 152-95
Instruction Manual
Updated 1/8/2019
Ver. 4.0
OFI Testing Equipment, Inc.
11302 Steeplecrest Dr. · Houston, Texas · 77065 · U.S.A.
Tele: 832.320.7300 · Fax: [phone] · www.ote.com
©Copyright OFITE 2015

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Intro..................................................................................................2
Description......................................................................................2
Components ...................................................................................3
Safety...............................................................................................4
Setup................................................................................................5
Test Procedure................................................................................6
Creating a Calibration Curve.........................................................8
Maintenance..................................................................................10
Warranty and Return Policy ........................................................ 11
Table of
Contents

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The OFITE Calcimeter is used to determine the amount of Calcium
Carbonate (CaCO3) and Magnesium Carbonate (Dolomite) in a sample of
alkaline earth carbonates such as oil well cores or drilled cuttings. Calcite
build up in drilling uids and in water treatment processes causes scaling
problems. Data from the OFITE Calcimeter can help determine the proper
chemical treatment.
This instrument complies with the ASTM D 4373 - 84 (Reapproved 1990)
Standard Test Method for Calcium Carbonate Content in Soils. This test
method is under the jurisdiction of ASTM Committee D-18 on Soil and
Rock and is the direct responsibility of Subcommittee D -18.13 on Marine
Geotechnics, published July 1984.
In the OFITE Calcimeter, calcium carbonate and magnesium carbonate are
reacted with 10 percent hydrochloric acid in a sealed reaction cell to form
CO2. As the CO2is released, the pressure build up is measured using either
a pressure gauge or a pressure recorder. During the calibration process,
a calibration curve is created by reacting HCl with pure, reagent-grade
CaCO3. By using a known weight of CaCO3reagent, you can determine
the relationship between the amount of pressure released and the weight
of CaCO3in the sample. Since all reaction cells are slightly different, this
relationship will be different for each cell. Therefore a calibration curve is
required to obtain accurate results.
The calcium carbonate content of soil (ASTM Procedure D 4373) is
determined by treating a 1 g dried soil specimen with HCl in the reactor
cell. The resulting pressure increase is then measured and compared to the
calibration curve to determine the total weight of CaCO3in the test sample.
Intro
Description

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Components #142-54 O-ring for Bleed-Off Screw
#152-95-1 Gauge with Cover, 30 PSI, 4" Diameter
#152-95-2 Bleed-Off Screw
#152-95-3 Cell Cap
#152-95-4 Reaction Cell
#152-95-5 O-ring for Cap
#152-95-6 Sample Cup
Optional:
#152-96-6 Mortar, 65 mL, Porcelain
#152-96-7 Pestle, Porcelain
#153-02 Brush, Graduate, 1.5" × 10.75"
#153-18 Graduated Cylinder, 10 mL × .2 mL, Glass
#153-55 Stopcock Grease, Silicone
#166-03 Hand-held Balance, 0 - 320 g × .1 g
#275-03 Hydrochloric Acid, 10%, 8 oz UN 1789
#285-00-1 Calcium Carbonate, 100 g

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Safety The Calcimeter test relies on the reaction of CaCO3with hydrochloric acid.
Hydrochloric acid is corrosive and may cause chemical burns. Use care in
handling the acid. Avoid contact with skin, eyes, and clothing. In the event
of exposure to skin or eyes, immediately ush with large quantities of water
for at least 15 minutes. Do not inhale vapors. Process hydrochloric acid
beneath a laboratory hood or in a well-ventilated area to reduce the risk of
inhalation. Wear appropriate safety equipment at all times.
Do not take internally. In the event of accidental exposure, get medical
attention immediately.
Refer to the Material Safety Data Sheet (MSDS) for more information on
Hydrochloric Acid

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Setup Begin by carefully unpacking the equipment. Inspect each piece to ensure
everything is clean and in good operating condition. Inspect the cell cap
o-ring for cracks or wear.
Gauge
Cell Cap
Bleed Valve
O-ring

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Test
Procedure
Before starting the test procedure, make sure the equipment is clean and in
good operating condition. Verify that a calibration curve is available for the
particular equipment to be used. If a calibration curve is not available, see
the “Creating a Calibration Curve” section on page 8 to construct one.
1. Obtain a sample of core, drilled cuttings, or other solids that are to be
analyzed. The sample should be dry and free of contaminants. Grind the
sample to 100 mesh or ner, using a mortar and pestle and a 100-mesh
sieve. If you do not know whether the sample has been dried, heat it in
an oven at 220°F (105°C) for 12 to 24 hours.
2. Weigh approximately 1.0 - 1.4 g of the sample to the nearest .001 g.
3. Load the test sample in the reactor cell.
a. Unscrew and remove the cell cap. Remove the acid cup from the
reaction cell.
b. Inspect the reaction cell and top. Make sure both are clean and dry.
c. Make sure the reaction cell o-ring on the top and the o-ring on the
bleed valve are in good condition. Use a light coating of vacuum
grease on the o-ring seals. Make sure all pipes or tubing connections
are tight and do not leak.
d. Hold the reaction cell in a horizontal position and slide one piece of
paper and its sample to the bottom.
e. Return the cell to the vertical position and brush the paper with a
small brush to remove traces of the sample, then remove the paper.
f. Fill the acid cup with 20 mL 10% hydrochloric acid. Carefully place
the cup into the cell. Be careful not to spill the HCl or get any on the
bottom of the cup.
g. Hand tighten the cell cap. Be careful not to splash any acid onto the
sample.
h. Open the bleed valve until the pressure reading is zero. Then close
the bleed valve tightly.
i. Turn the cell back to the horizontal position to release acid from the
cup.
4. Turn the reaction cell back to vertical and start timing the test. This will
start the reaction between the HCl and the CaCO3.

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5. At 30 seconds, record the pressure as “CaCO3Pressure”. If the test
sample contains any dolomite, there will be a pause, then a slow, second
rise in pressure. Swirl the reaction cell and allow sufcient time for the
reaction to nish. The reaction is complete when the pressure stops
increasing. This should happen in 30 to 45 minutes. The nal pressure
value is the total CaCO3pressure plus the dolomite pressure. To
calculate the dolomite pressure, subtract the CaCO3pressure (30 second
reading) from the total pressure (30 - 45 minute reading).
6. Refer to the graph below to interpret the pressure readings.
7. Use the equations below to calculate the percentages of CaCO3and
dolomite. For values of “Slope” refer to the “Creating a Calibration Curve”
section below.
%CaCO3=
%Dolomite =
(Pressure Reading, PSI) (100)
(Sample Weight) (Average Slope)
(Total Pressure - CaCO3Pressure) (100) (.92)
(Sample Weight) (Average Slope)

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Creating a
Calibration
Curve
The volume of a calcimeter reaction cell determines the relationship between
the pressure increase and the amount of CO2released. This relationship
is constant for a given reaction cell. The calibration curve and calculated
calibration factor are used to convert the amount of pressure released
into a percentage of calcium carbonate. All points on the calibration curve
represent 100% CaCO3(for that sample weight). Any number of samples can
be used to construct the calibration curve. The following are recommended
for accuracy.
1. Prepare ve sets of duplicate specimens with the following masses of
CaCO3:
0.2 ± 0.01 g
0.4 ± 0.01 g
0.6 ± 0.01 g
0.8 ± 0.01 g
1.0 ± 0.01 g
2. Load a calibration sample.
Perform the procedure outlined in the “Test Procedure”, step 3.
3. Tip the cell and allow acid to run out of the cup onto the sample. Swirl the
cell gently and continuously until a constant pressure is obtained. This
will take at least 10 minutes. Keep the reactants in the lower part of the
cell to avoid getting acid into the pressure gauge or pressure transducer.
As soon as the reaction has started, observe the rapidly rising pressure.
Record the peak pressure to the nearest 0.1 PSI (0.5 kPa) as the CaCO3
pressure for the sample weight used.
If a mechanical shaker is available, it may be used to agitate the cell
rather than swirling the reactants. Agitate the sample for 10 minutes.
4. Repeat steps 2 and 3 for each of the remaining samples you prepared in
step 1.
5. For each sample create a plot on linear graph paper. On the x-axis plot
grams of CaCO3 and on the y-axis plot the nal pressure in PSI. Draw
a straight line through the average of the points. The graph on page 9
shows a sample calibration curve.
6. Because the relationship between pressure and sample size is linear, you
may assume the curve to be a straight line with a constant slope. As the
graph on page 9 illustrates, the slope of the curve is 2 PSI / .1 g CaCO3,
or 20 PSI / 1.0 g CaCO3, resulting in a slope of 20. Therefore, the
calibration factor is .05 × 100 = 5. This number is the slope or average
slope for the equipment. It is a function of the volume of the reaction cell.

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As shown by the equations below, the slope can be written as a “Cell
Factor” to multiply the pressure reading to directly obtain percentages of
Calcium Carbonate and Dolomite.
As described above Slope = 20 PSI for a 1g sample therefore
% CaCO3= = 5 × Pressure
% Dolomite =
or
% Dolomite = 4.6 × (Total Pressure - CaCO3Pressure)
Sample Calibration Curve
(Pressure) (100)
(1 g) (20)
(Total Pressure - CaCO3Pressure)(.92)(100)
(1 g × 20)

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Maintenance After each test, thoroughly clean the cell and acid cup with water and a mild
soap. Use only alcohol-free cleaners. Alcohol can damage the plexiglass
cell.
Testing For Leaks
Leaks in the pressure system are the most common case of inaccurate
readings.
1. Periodically inspect the reaction cell and replace the o-rings if they are
dry, cracked, or worn.
2. Clean the pipe-thread connection between the reaction cell top and
the pressure gauge or transducer with a brush and soap suds. If
repairs are necessary, disassemble the pipe-threaded connection
between the reaction cell and the gauge or transducer. Use teon
tape to re-seal the connection.
3. Check for plugging in the connection between the reaction cell and
the gauge or transducer. Also check the gauge entrance or the
transducer barrel and diaphragm for build-up of calcium deposit over
long periods of time. A warm bleach wash should clean these parts.
4. To check for leaks, pressurize the instrument as described in
“Creating a Calibration Curve” above using a .6 g sample. Let the
unit stand for at least one hour. The pressure within the reaction cell
should remain stable unless leaks are present.
Calibration Data Does Not Give a Straight-Line
If there are no leaks in the system, but results are not giving a straight-line
calibration curve or data is otherwise questionable, check the following:
1. Make sure the scale or balance is clean. Shield the balance from air
currents and vibration as much as possible when weighing samples or
CaCO3for calibration.
2. Check the reaction cell for contaminants. Be sure the cell is clean
and dry.
3. Check for impurities in reagents. Moisture in CaCO3will result in low-
pressure readings.

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Warranty:
OFI Testing Equipment, Inc. (OFITE) warrants that the products shall be free from liens and defects in
title, and shall conform in all respects to the terms of the sales order and the specications applicable
to the products. All products shall be furnished subject to OFITE’s standard manufacturing variations
and practices. Unless the warranty period is otherwise extended in writing, the following warranty shall
apply: if, at any time prior to twelve (12) months from the date of invoice, the products, or any part
thereof, do not conform to these warranties or to the specications applicable thereto, and OFITE is
so notied in writing upon discovery, OFITE shall promptly repair or replace the defective products.
Notwithstanding the foregoing, OFITE’s warranty obligations shall not extend to any use by the buyer
of the products in conditions more severe than OFITE’s recommendations, nor to any defects which
were visually observable by the buyer but which are not promptly brought to OFITE’s attention.
In the event that the buyer has purchased installation and commissioning services on
applicable products, the above warranty shall extend for an additional period of twelve
(12) months from the date of the original warranty expiration for such products.
In the event that OFITE is requested to provide customized research and development for the buyer,
OFITE shall use its best efforts but makes no guarantees to the buyer that any products will be provided.
OFITE makes no other warranties or guarantees to the buyer, either express or implied,
and the warranties provided in this clause shall be exclusive of any other warranties
including ANY IMPLIED OR STATUTORY WARRANTIES OF FITNESS FOR PURPOSE,
MERCHANTABILITY, AND OTHER STATUTORY REMEDIES WHICH ARE WAIVED.
This limited warranty does not cover any losses or damages that occur as a result of:
• Improper installation or maintenance of the products
• Misuse
• Neglect
• Adjustment by non-authorized sources
• Improper environment
• Excessive or inadequate heating or air conditioning or electrical
power failures, surges, or other irregularities
• Equipment, products, or material not manufactured by OFITE
• Firmware or hardware that have been modied or altered by a third party
• Consumable parts (bearings, accessories, etc.)
Returns and Repairs:
Items being returned must be carefully packaged to prevent damage in
shipment and insured against possible damage or loss. OFITE will not be
responsible for equipment damaged due to insufcient packaging.
Any non-defective items returned to OFITE within ninety (90) days of invoice are subject to a
15% restocking fee. Items returned must be received by OFITE in original condition for it to
be accepted. Reagents and special order items will not be accepted for return or refund.
OFITE employs experienced personnel to service and repair equipment manufactured by us, as
well as other companies. To help expedite the repair process, please include a repair form with all
equipment sent to OFITE for repair. Be sure to include your name, company name, phone number,
email address, detailed description of work to be done, purchase order number, and a shipping address
for returning the equipment. All repairs performed as “repair as needed” are subject to the ninety (90)
day limited warranty. All “Certied Repairs” are subject to the twelve (12) month limited warranty.
Returns and potential warranty repairs require a Return Material Authorization (RMA)
number. An RMA form is available from your sales or service representative.
Please ship all equipment (with the RMA number for returns or warranty repairs) to the following address:
OFI Testing Equipment, Inc.
Attn: Repair Department
11302 Steeplecrest Dr.
Houston, TX 77065
USA
OFITE also offers competitive service contracts for repairing and/or maintaining your lab
equipment, including equipment from other manufacturers. For more information about
our technical support and repair services, please contact techservice@ote.com.
Warranty and
Return Policy