Sentry ISOLOK MSA Instruction manual

Original Instructions
Installation, Operation
&Maintenance Manual
ISOLOK MSA Sampler
Point Samplers
S-AS-IOM-00300-8 10-22

2 Sentry Equipment Corp
Do not install, maintain, or operate this equipment without reading, understanding, and following the
appropriate Sentry Equipment Corp instructions. Otherwise, injury, damage, or both may result.
Copyright
© 2022 by Sentry Equipment Corp. All rights reserved. All product and company names are property of their respective
owners. This document contains proprietary information. No part of this document may be photocopied or reproduced
without the prior written consent of Sentry Equipment Corp.
Limit of Liability
Sentry Equipment Corp, its employees, agents, and the authors and contributors to this document specically disclaim
all liabilities and warranties, express or implied (including warranties of merchantability and tness for a particular
purpose), for the accuracy, currency, completeness, and/or reliability of the information contained herein and/or for the
tness for any particular use and/or for the performance of any material and/or equipment selected in whole or part
with the user of/or in reliance upon information contained herein. Selection of materials and/or equipment is at the
sole risk of the user of this publication.
Note
The information contained in this document is subject to change without notice.

ISOLOK MSA Sampler 3
Table of Contents
Safety Information .........................................4
General Safety Precautions .................................5
General Description ........................................6
Installation ................................................7
Selection of Installation Location.....................................7
Sampler Installation .................................................7
Controller Installation................................................8
Inspection...........................................................11
Operation..................................................11
Initial Cleaning ......................................................11
Starting the Sampler.................................................11
Maintenance ...............................................12
Daily Cleaning .......................................................12
Weekly Inspection ...................................................13
Complete Sampler Disassembly and Maintenance ....................13
Controller Maintenance..............................................14
Standard Warranty .........................................17
Customer Support..........................................17
Appendix: Installation & Operation on a Milk Truck...........18
Sampler and Controller Installation...................................18
Typical Operation Procedure .........................................20

4 Sentry Equipment Corp
Safety Information
Please read the entire manual before attempting to unpack, set up, or operate this product. Pay careful attention to all
Warnings, Cautions, and Notes. Failure to do so could result in serious personal injury and/or equipment damage.
Use of Hazard Information
If multiple hazards exist, the signal word corresponding to the greatest hazard shall be used.
Denitions
DANGER indicates a hazardous situation which, if not
avoided, will result in death or serious injury.
WARNING indicates a hazardous situation which, if not
avoided, could result in death or serious injury.
CAUTION, used with the safety alert symbol, indicates a
hazardous situation which, if not avoided, could result in
minor or moderate injury.
NOTICE is used to address practices not related to personal
injury.
ÂNOTE
Information that requires special emphasis.
ÂTIP
Alternate techniques or clarifying information.
SHALL:
This word is understood to be mandatory.
SHOULD:
This word is understood to be advisory.

ISOLOK MSA Sampler 5
General Safety Precautions
Product Selection, Installation, and Use
Improper selection, installation, or use can cause personal injury or property damage. It is solely the responsibility of users,
through their own analysis and testing, to select products suitable for their specic application requirements, ensure they are
properly maintained, and limit their use to their intended purpose.
Follow proper local, state, and federal regulations for proper installation and operational requirements.
Always use caution and common sense when working with any chemical. Read the product label and Material Safety Data
Sheets (MSDS) carefully and follow the instructions exactly.
Potential Equipment Hazards
Hot surfaces! This equipment may have very hot surfaces. If an operator contacts a hot surface, injury may occur. Use
protective clothing to prevent injury. If other equipment comes in contact with a hot surface, damage to the equipment may
occur. Ensure the area around this equipment is kept clear to prevent damage from occurring.
High pressures! This equipment may contain uids at very high pressures. Prior to installing, removing or maintaining this
equipment, ensure that the equipment is isolated from all connecting piping, the equipment is depressurized, the contents
have been drained, and the equipment is cool.
Moving parts! This equipment may contain moving parts. All drive guards and doors must be secured in place when this
machine is being operated.
Equipment rated TX. Equipment maximum surface temperature depends
on operating conditions. Ensure maximum surface temperature shall stay
below ignition temperature of dust or gas atmosphere where it is installed
based on process conditions. Failure to comply could result in an explosion,
causing serious injury or death to personnel and damage to equipment.
If the sampler is mounted directly to a non-electrically conductive surface,
sampler shall be bonded to a grounding electrode. Failure to comply
could result in sparking, which could lead to an explosion, causing harm to
personnel and equipment.
If the sample container is removed from the sampler, do not insert any
body part or other item into the sample discharge port. Crushing will
occur.
To ensure proper sampler operation, be sure
the sampler is installed in a pipe large enough
for the sampler plunger to extend without
impacting the pipe. Failure to comply will
result in equipment damage and poor sample
quality.
Sampler may require a two-person lift. Please
refer to the General Arrangement drawing for
weight and dimensional information.

6 Sentry Equipment Corp
General Description
Read these instructions completely before proceeding to assemble, install or operate this machine. This machine should
be installed, operated and serviced by qualied individuals. All drive guards and doors must be secured in place when
this machine is being operated. Follow proper local, state and federal regulations for proper installation and operational
requirements.
The Sentry® ISOLOK® MSA sampler is designed for sampling sanitary products such as Grade A or industrial grade raw
or processed milk. The ISOLOK MSA sampler can be used in a process line or on the wall of a vessel or reactor. It can
also be installed on road tankers transporting liquid milk. See the Appendix of this manual for information specic to
milk truck applications.
Other applications of this sampler include low volume chemical sampling or biofuel/hydrocarbon sampling.
The sampler is powered by compressed air and operated by an electrical cycle controller that provides adjustable,
time-based sampling rates. The controller circuit has been designed to provide an adjustable time delay before the
sampler begins operation. Delay before the rst cycle adjustment range is approximately one-tenth of a second
to 10 seconds. The objective is to allow product trapped in a hose or piping to pass the sampler before operation
begins. During initial delay, the controller solenoid valve is energized, causing the sampler plunger to extend into the
mounting tee, where it can be ushed by product ow.
The ATEX Temperature Class rating is dependent upon process uid temperature. Reference the following chart:
TX maximum
temperature
T2 572°F (300°C)
T3 392°F (200°C)
T4 275°F (135°C)
T5 212°F (100°C)
T6 185°F (85°C)
ÂNOTE
The working pressure of the air cylinder is 120 psig with a max cycle rate of 240 cycles/min on a continuous duty cycle.
Additionally, actuating gas needs to be a non-combustible neutral gas and the working temperature must be between -4F
to 149F (-20C to 65C).
ÂNOTE
Figures in this manual may dier from actual purchased equipment. Please refer to the drawings in the appendices of this
document.
The sampler is powered by compressed air and is typically operated by an electrical cycle control that provides an
adjustable time or ow-based sampling rate. Other operating mediums are available.
The sampler normally connects to the sampler controller by two 16-foot lengths of exible tubing. It mounts onto a
1-1/2 inch Tri-Clamp ferrule that is specially close-coupled to the line, usually by adding a specialized line-mounting
adapter tee into the piping.
ÂNOTE
Figures in this manual may dier from actual purchased equipment. Please refer to the drawings in the appendices of this
document.
ATEX Ratings:
Ex h IIB T5…T2 Gb
Ex h IIIC T83°C…T300°C Db
-20°C ≤ Ta ≤ +65°C

ISOLOK MSA Sampler 7
Specications
The ISOLOK MSA sampler takes 0.5 cc of sample per cycle. With the standard controller, it can be cycled at any rate
between 180 samples per minute maximum and 2-1/2 samples per minute minimum. It meets sanitary construction
standards and carries the 3-A symbol.
Sampler Controller
Housed in a stainless steel enclosure, the ISOLOK MSA sampler controller uses solid state timing to actuate a three-way
solenoid valve that provides a compressed air pulse to operate the sampler. Services required to control the sampler
are a source of compressed air at 50 psi minimum to 120 psi maximum, and a direct current electric supply, 12 VDC.
Cycle rate [timing] adjustment is provided by the sampler controller dial.
Sample Collection Containers
Refer to your system application drawing for container mounting adapter or alternate sample collection methods
provided on your specic equipment.
Bottles
Sample collection bottles in 4, 8 and 16 oz (125, 250 and 500 ml) capacities with 24 mm threads are available and
screw directly onto the sampler body.
Bag Adapter or Vial Adapter
A typical ISOLOK MSA sampler includes a sample bag mounting adapter or a vial adapter. Either mounts onto the
discharge port in the sampler body. The bag adapter holds wire-tie plastic sample bags, while the vial adapter mounts
single-service plastic sample vials.
BAG ADAPTER. Intended to be used with single service sanitary plastic bags that close with a built-in wire tie. Sizes
up to about an 8 oz (250 ml) capacity can be supported by carefully folding the open bag mouth and wire around
the small diameter below the drip shield. Larger capacity bags are available, but should be approached with
caution, as the weight of larger samples could cause a bag to pull o of the adapter. Excessive twisting of the wire
tie of a large bag also could distort the closure tie to the point where the bag could leak during later handling.
VIAL ADAPTERS. Intended to be used with single-service sanitary plastic sample vials. For the greatest simplicity in
setting the sampling rate for a given farm load, use the largest capacity vial that is practical.
Like all connections, Sentry ISOLOK samplers must be initially installed and periodically inspected to ensure all
connectors, clamps and fasteners are rmly tightened. If screws or connectors are not propertly secured, the sampler
could leak or sustain damage.
Follow your plant safety procedures whenever maintenance or inspection is required on this sampler.
Do not weld, machine or otherwise modify the sampler or controller in any manner. Consult Sentry Equipment before
considering any changes to the sampler.
Installation
Selection of Installation Location
Both the sampler and sampler controller are intended to be installed inside equipment cabinet(s). For milk truck
applications, these cabinets are customarily part of milk pickup tankers. (See Appendix of this manual for installation
on a milk truck.) Most sanitary standards require that these cabinet(s) be designed to protect pumps, valves and other

8 Sentry Equipment Corp
equipment from road dirt and damage, or in case of electric drive motors for pumps, from excessive exposure to
cleaning sprays.
Select a location to install the sampler where the material in the process stream is well mixed. Location of the sampler
and controller is very important for accurate sampling results. They should be as close together as practical, within
sight of each other, and protected from weather, trac damage and normal work activities in the area.
When selecting a sampler location, ensure the sample collection container will clear vertical lines (or other
obstructions) when mounted onto the sampler. The sampler can be used on a pipe or tank running horizontally,
vertically or at an angle, but the axis of the sampler body must be horizontal.
Sampler Installation
Install the sampler by using a line mounting tee that positions the sampler nose (front of body) close to the main
sample ow stream. In this position, samples are taken directly from moving product. A short 1-1/2-inch ferrule clamp
port on the side of the adapter tee (as recommended and/or furnished by Sentry Equipment Corp) provides the
proper line mounting location for the sampler.
If a standard Sentry adapter tee cannot be used, a 1-1/2-inch tri-clamp style ferrule clamp port must be devised. The
ferrule branch should be just long enough to accept the sampler mounting clamp without interference. The factory
standard is 5/8-inch from the ferrule face to the outside of the line.
Refer to your system application drawing included with this manual and the following section in this manual to install
the sampler controller in its most eective location.
1. The line where the sampler is to be located can be horizontal, vertical or at any angle. The location selected must
mount the sampler body with its long axis horizontal and with sucient clearance beneath the unit for ease of
sample container mounting and exchange.
2. Disconnect the piping, insert the sampler mounting tee, and reconnect the piping to the tee. Attach the sampler
to the short 1-1/2-inch tri-clamp ferrule port on the tee with the clamp and gasket.
3. Check to ensure the sampler body is horizontal. Loosen the tee and rotate it if required. Install the air line to the
tting on the sampler barrel. Use 36 inches of the length of 1/4-inch OD exible polyurethane tubing provided.
4. Press the tube end over the barb tting by hand. No external clamps are needed. Use no more than 36 inches
of connecting airline; shorter if practical. Remember, the sampler must be removed from the piping for daily
cleaning. Air lines longer than 36 inches may restrict the sampler’s maximum cycle rate.
5. If a bag or vial adapter will be used, insert the o-ring seal into the sampler body port. It seats into a groove above
the threads. Screw the adapter into the 24 mm threaded discharge port of the sampler. Turn in rmly, by hand. DO
NOT USE TOOLS. Excess force could bind or gall stainless threads.
Controller Installation
Refer to your system application plus the controller group drawings included with this manual.
Select a location in an equipment cabinet, preferably a“dry” compartment area where using the sampler controller will
be convenient for the operator, yet protected from direct exposure to cleaning solutions or wash water sprays.
Avoid positioning the sampler controller in any location where milk, water, cleaning solutions,
tools, etc. could cause damage.

ISOLOK MSA Sampler 9
1. When checking locations, temporarily attach the L-shaped mounting bracket to the back of the controller, using
the nuts provided.
2. Be sure the controller is far enough back inside the compartment to allow the door to close without hitting or
rubbing against the controller.
3. Check to ensure the air line will reach the sampler location without interference with other equipment in the
compartment. The sampler connection line is a 36-inch length of 1/4-inch OD exible tubing. This air line length
should be kept as short as possible to permit fastest cycle rates.
Mounting
Sampler may require a two-person lift. Please refer to the General Arrangement drawing for weight and dimensional
information.
When the best location for the sampler controller has been determined, mark the position of the mounting bracket
onto the surface. Remove the controller from the mounting bracket. Hold the bracket in position and mark the
location of the four mounting holes onto the compartment wall.
Fastening
Drill four mounting holes to accept the fasteners you select to hold the bracket. Use all four holes and largest fasteners
(screws, bolts, etc.) available to withstand the severe vibration usually encountered in this application.
Tanks with Bulkheads
Walls that seal a wet compartment from a dry area require special handling. The air supply line cannot be routed
around a sealing bulkhead wall without the danger of pinching the tube or blocking the door.
Wall Penetrations
The following procedure is suggested whenever air tube must be routed through a wall between compartments.
Since tank compartment designs vary, this is a general guide intended to be combined with your experience and local
practices.
1. Locating the hole between compartments: Determine the best place to pass the tube between compartments
after you have decided on a location for both the sampler and sampler controller. Be sure the hole location avoids
interference, pinch-points or wear on exible line. Choose a hole location that provides the shortest practical
distance between the sampler and controller. This should give maximum slack in the tube for later mounting and
handling of the sampler.
2. Protecting and sealing tube: Each Sentry ISOLOK sampler includes two bulkhead grommets as standard. If
additional grommets are required, contact Sentry Equipment Corp. Alternately, protective collars can be made on-
site.
3. Single wall bulkhead: Drill a 3/8-inch (9.5 mm) diameter hole. Remove burrs and install a grommet in the hole.
Feed the tube through the grommet to its approximate nal location.
4. Double wall bulkhead: Drill two 3/8-inch (9.5 mm) diameter holes exactly opposite each other to form a passage
through the wall. Remove or push aside any insulating material between the walls that might interfere with the
grommets. Use a pair of grommets, one for each side of wall. Follow the same installation procedure as a single
wall installation, provided above.

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Electrical Power Connection
The sampler controller requires a 12 VDC (direct current) power supply. Maximum draw is less than 1 amp when the
controller is operating.
1. GROUNDING: A separate ground wire is provided with each electrical power supply package.
a. AC package: Connect the GREEN ground wire from the negative terminal (3/16 in) on the back of the controller
to the 3/16 in ground terminal of rectier/transformer.
b. DC package: Connect the GREEN ground wire from the negative terminal (3/16 in) on the back of the
controller to suitable chassis ground.
2. STARTING AND STOPPING SAMPLER: The sampler should operate only when product is owing.
a. Systems using the AC power supply package to provide a direct current supply to the sampler controller
automatically will start and stop with external signal.
3. Sampler systems intended to operate using a DC power supply can use the ON/OFF switch on the face of the
sampler controller to manually turn the sampler on and o in conjunction with product ow.
Always disconnect the power lead from the rear of the sampler controller before removing the cover. Although voltages
within cycle control are not dangerous, accidentally shorting exposed terminals to the box can cause serious damage to the
equipment.
4. ELECTRICAL OVERLOAD PROTECTION: The sampler controller includes a current limiting device. This device
automatically disconnects power to the controller in the event of an accidental overload or short circuit. Identied
as “AutoFuse”, this device opens the power circuit any time current draw exceeds 2 ampere (at 68°F).
DC Power Supply Package (standard)
This parts package is used with a 12 volt supply. Install this electrical supply using the following steps:
1. Attach insulated, stranded wire (No. 18 AWG or larger) to a non-switched terminal, such as a non-grounded battery
terminal or equivalent.
2. Run wire lead to the 1/4 in spade-type terminal [+] on back of the cycle controller.
AC Power Supply Package (optional)
This parts package is used with 230 VAC supply and recties and transforms 230 VAC to 12 VDC (at 1/2 amp) to supply
the sampler controller. Interlocking to 230 VAC electrical service also automates the “start-stop”sampling function.
Polarity
The 12VDC output from the AC power supply is positive. The controller is wired for operation on“hot” positive with
negative to ground. If the sampler controller does not cycle when 230 VAC is ON to the power supply, check the
ground continuity from the power supply base to the compartment wall. Also, check connections on the wire lead
from the power supply to the sampler controller box.
Air Supply Connection
A source of compressed air is required at 50 psi (344 KPa) minimum, up to 120 psi (827 KPa) maximum. The air supply
and piping selected should be capable of providing up to 1 cubic foot of air per minute of sampler operation. The air
supply should be reasonably clean and free of water.

ISOLOK MSA Sampler 11
Air Supply Pressure
The sampler is designed to operate best at a regulated pressure of 40 psi (275 KPa). The regulator inside the controller
has been factory set to provide 40 psi to the sampler and should not require eld adjustment. However, if problems
occur and are attributable to variation in the air pressure to the sampler, regulated pressure can be checked and
readjusted as follows:
1. Remove the 1/8 in plug from the side of the regulator body. Install an accurate pressure gauge on this port.
2. With the air supply ON and sampler cycling every 2 seconds, the gauge should read 40 psi between cycles.
3. If the gauge does NOT read 40 psi, open the controller enclosure and readjust as follows:
a. Pull the adjusting knob upward to release the setting.
b. Turn the knob while the sampler is cycling until the gauge reads 40 psi between cycles. Clockwise [+] rotation
increases, and counter-clockwise [-] rotation decreases the system pressure.
c. Push the adjusting knob downward to lock the pressure setting.
d. Turn the sampler controller OFF and disconnect the electrical power supply. Shut o the air supply. Remove
the gauge, replace the plug and close the controller cover.
Inspection
After installation, the sampler periodically should be checked for proper operation and to ensure that any wear is
detected so proper preventive maintenance can be performed. The Maintenance section of this manual describes
recommended procedures fo daily, weekly and other cleaning and maintenance.
Start-up Inspection
With electrical power and compressed air ON, set the dial pointer to approximately 40 percent of the maximum rate
(in the 10 o’clock position). Remove the sampler from the line. Turn the controller switch to ON for a few seconds and
observe sampler operations.
Each time the sampler cycles, the plunger will extend out of the body approximately 7/8 in” (22 mm), then withdraw.
Each time the plunger moves in or out, you should hear a rm “click” as the piston bottoms at each end. The plunger
dwells inside the sampler body between cycles.
A complete plunger stroke occurs in about 1/5 (0.2) second. If plunger seals are dry, a sluggish or incomplete stroke
may occur. See the Maintenance section of this manual for service information
Operation
Initial Cleaning
1. Remove the sampler body.
2. Using approved sanitary methods, clean the parts that have contact with product (i.e., plunger rod, front face,
interior and discharge ports of the sampler body).
3. Wipe a very thin lm of approved dairy lube (white grease, CIP lube or Vaseline) on the four plunger O-ring seals,
plus the rod and piston O-rings.

12 Sentry Equipment Corp
4. Reassemble the sampler and clamp-mount onto the piping tee.
Starting the Sampler
ÂNOTE
Delayed start is designed to avoid sampling product which may be trapped in a transfer hose or other piping at the
conclusion of pumping a load. Delay before the rst sample should be adjusted to the minimum time needed to clear the
hose of standing product and ensure that product at the sampler is from load being pumped, not carryover from a previous
producer.
Delay time adjustment is made by changing the setting on the delay potentiometer located in the upper left-hand corner of
the timing module.
Turn o power to the sampler controller before opening the enclosure or making internal adjustments.
1. With the power OFF and the controller enclosure open, locate the delay potentiometer on the timer module. The
dial is calibrated in percentages [%] of 0-100. Adjust by turning the knob with a screwdriver in the slot provided.
2. Start delay adjustment (0.1 - 10 seconds).
3. Turn clockwise to increase, counterclockwise to decrease
delay.
4. Start delay is a single turn potentiometer. It will not turn more
than a nominal 270°. Adjustment is 1/10 second minimum to
10 seconds maximum.
5. When the sampler controller is operated through a DELAY-
SAMPLE OFF sequence, allow approximately 10 seconds for
the delay timer to reset before starting the next sampling
operation.
6. After adjusting the delay time, replace the controller cover
securely onto the box.
Maintenance
Refer to your specic group drawing that is included with this manual.
The ISOLOK MSA sampler should be cleaned and checked at daily and weekly intervals for proper operation and to
ensure any wear is detected so preventive maintenance can be performed.
Never use pipe wrenches, vise-grip pliers or other marking or abrasive tools on your sampler.
Daily Cleaning
Clean the sampler by removing the unit from the line tee, partially disassemble it, and manually clean it. Typical steps
for cleaning the sampler include:
50
100
0

ISOLOK MSA Sampler 13
1. Unclamp and remove the sampler from its mounting tee. Remove the gasket.
2. Remove any sample container adapter, including the O-ring seal within the body port.
3. Disconnect the clamp between the sampler body and barrel. The spring will force the plunger and barrel away
from the body.
4. Pull the plunger and spring out of the barrel. Leave the barrel connected to the air line tubing.
5. Remove four plunger seal O-rings from the grooves in the plunger by squeezing the O-ring diameter between
the thumb and nger and rolling the rings out of their grooves. Two front plunger seal O-rings should be
rolled forward, o the plunger. Two back seals can be rolled into the sample collecting ring on the plunger for
convenience during cleaning. Remove the rear rod seal O-ring and piston seal O-ring from the plunger.
6. Spray or brush clean/sanitize the body, plunger, spring, all seals and gasket, as well as any port adapter and its seal,
in approved sanitary procedure.
7. Replace the rod seal and piston O-ring into their grooves. Roll the O-ring plunger seal rings into the grooves on
the plunger. Wipe a light lm of approved dairy lubricant onto all six O-ring seals. Add a light lm of lubricant on
the inside of the air cylinder barrel.
8. Assemble the spring on the plunger and insert the plunger into the sampler body.
9. Slip the barrel over the plunger piston. Press the barrel against the sampler body to compress the spring. Install
the clamp. Replace any port adapter, including the O-ring seal.
10. Replace the line tee gasket and install the sampler and clamp in place. The sampler body should be horizontal,
with the sample discharge port pointing down.
Weekly Inspection
With the sampler removed from the line, turn the compressed air and sampler controller power on. Between cycles,
the plunger dwells retracted. When a cycle is initiated, the sampler plunger should extend 7/8 in (22mm) from the
sampler body and then retract inside the body. If the seals are completely dry, a sluggish or incomplete stroke may
occur.
Lubrication
Cleaning normally will remove all lubrication. Wipe a thin lm of approved dairy lubricant, such as white grease, CIP
lube or Vaseline, onto all seals. Continued short stroke, incomplete cycling or sluggish extension may indicate dirt or
liquid in the barrel, leaks in the air line, or damage to metal parts.
Plunger Seals
Inspect the O-ring seals on the plunger. Replace any that are scued, scored or with ats worn on OD. Carefully insert
the plunger through the bore of the body. Seals should move through smoothly, but with light resistance. Little or no
resistance indicates the rings are not properly sealing and should be replaced. The bore of the body where the seals
ride also should be smooth and free of nicks and scratches.
Complete Sampler Disassembly and Maintenance
A complete disassembly, inspection and cleaning of the ISOLOK MSA sampler should be performed as required. Work
on a clean, well-lighted bench area with a copy of the sampler group assembly drawing for reference.

14 Sentry Equipment Corp
Disassembly
Disassemble as for cleaning. Remove any sample container adapter, including the O-ring seal within the body port.
Remove all six O-ring seals and inspect for wear, at spots or cuts and tears. Replace if required.
1. Test the four plunger seals and rod seal by carefully inserting the plunger through the rear of the body. You should
feel resistance.
2. Carefully remove the O-rings, examining for ats, cuts or other signs of wear. Clean the seal recesses.
3. Inspect the O-ring piston seal. If the seal is deformed, scored or has ats worn on the outside diameter, replace it.
4. Inspect the bore of the air cylinder barrel for scoring or wear. Wipe it clean using an approved solvent, if necessary.
Light score marks can be polished using ne crocus cloth. Be careful not to remove excess metal anywhere. Heavy
score marks that do not easily polish out will render the barrel inoperable, and the barrel should be replaced.
5. Insert the piston, with the lubricated O-ring seal in place, into the sampler barrel. Hold the piston square. It should
t airtight. Check by holding your nger over the air tting port on the barrel while moving the piston back and
forth. A leaking piston seal should be replaced.
Resassembly
1. Reassemble the four plunger seals, rod seal and piston seal O-rings onto the plunger.
2. Apply a thin lm of the approved dairy lubricant to all six seals. Assemble the spring onto the plunger and insert it
into the sampler body.
3. Lightly lubricate the inside of the sampler barrel. Slip the barrel over the piston and compress against the body.
Cycle testing at this point is recommended to ensure proper operation.
4. Replace any bottle or bag adapter after inserting the O-ring seal at the base of the threads in the sampler body.
Cycle testing at this point is recommended to ensure proper operation.
Controller Maintenance
Cleaning
DO NOT subject the sampler controller to direct contact with cleaning solutions or detergents. DO NOT hose it down
or otherwise steam or spray clean water on the controller. Repeated contact with water and/or caustic cleaners may
cause a malfunction. CLEAN GENTLY.
Visual Check – Daily
1. Check for water in the lter bowl.
2. With the air pressure on, push the spring valve on the bottom of the bowl to blow out any accumulated moisture.
Visual Check – Weekly
1. Check air lines for wear, cracks or leakage.
2. Check mounting bolts and fasteners to ensure they are tight.
3. Check the controller dial knob and air lter-regulator-solenoid assembly to ensure they are tight.
4. Check rubber “boot” on the ON/OFF switch. Replace if it is worn or torn.
5. With the air pressure OFF, unscrew the air lter bowl and remove any accumulated debris.

ISOLOK MSA Sampler 15
Component Replacement
Disconnect electrical power supply before opening or working inside the sampler controller enclosure.
Timing Components
The timer is a solid state module and non-repairable. If the controller fails to function, rst determine if the problem is
electrical. If electrical, check for power supply ON, and for continuity through ON/OFF switch.
Cycle Timer
If the sampler controller fails to function at any setting of load dial, the timer probably needs to be replaced.
Replacement timers are available from Sentry Equipment Corp. Follow the controller circuit diagram to properly
connect a replacement timer.
A 1/4-inch nut is used to hold the timer in place against a rubber base sheet. The nut is self-locking and should be tightened
only until the timer is secure. DO NOT OVERTIGHTEN as this could cause the timer case to crack and allow damaging
moisture inside.
Any time connections are removed from the timing module for any reason, always refer to the circuit diagram when
reconnecting wires to timer terminals.
Controller Sample Rate Potentiometer
The controller sample rate potentiometer is a round component with brown wire leads on two of three lugs. If
controller operation becomes erratic (e.g., cycles at some load size dial settings but not at others, or dierent sampling
rates at the same setting), the potentiometer is the probable cause. It is not repairable and must be replaced.
Replacement parts are available from Sentry Equipment Corp.
To replace:
1. Unplug the two brown wire leads from insulated terminals on the timer module.
2. Release the two set screws in the black knob and remove the knob.
3. Remove the rubber seal hex nut on the potentiometer shaft and on the ON/OFF switch toggle, both from outside
of the controller.
4. Inside the controller, remove the subplate holding switch, autofuse and potentiometer.
5. Remove the hex nut and lockwasher holding the potentiometer to the subplate. Remove the potentiometer.
6. Insert the replacement potentiometer shaft through the subplate. Rotate until the tang enters the slot on the
subplate. Attach it with the lockwasher and hex nut.
7. Reassemble the subplate through the holes in the controller cover. Install the rubber seal hex nuts on the
potentiometer and switch.
8. Reconnect the potentiometer lead wire terminals to yellow and brown insulated timer leads.
9. Reassemble the controller cover into box.

16 Sentry Equipment Corp
Setting and Checking the Replacement Potentiometer
1. Rotate the bare potentiometer shaft to its maximum counterclockwise position. Slip the black knob onto the shaft.
Line up the pointer with the end of the sample frequency scale on the [+] side. Tighten the two set screws on the
knob.
2. Rotate the knob from minimum to maximum setting to make sure it moves smoothly.
On/O Switch
If switch becomes undependable or fails completely, it must be replaced. Replacement switches, complete with all
necessary wire leads and terminals, are available from Sentry Equipment Corp.
1. Disconnect all power to the sampler controller. Remove the rubber seal hex nut from the toggle on the outside of
the controller. Release two set screws on the controller knob and remove the knob. Remove the rubber seal nut on
the potentiometer shaft.
2. Open the sampler controller. Remove the subplate holding switch, autofuse and potentiometer. Remove the hex
nut holding the switch to the subplate.
3. Disconnect the two switch leads from the spade terminals. Remove the switch.
4. Insert the replacement switch and reassemble in reverse order.
Pneumatic Components
Replace either the air pressure regulator or the solenoid air valve using the following steps:
1. Disconnect the air line tubing to the sampler. Disconnect the incoming compressed air supply line. Open the
sampler controller enclosure. Disconnect the wire leads between the cover and box. Completely remove the cover
to a safe, clean area.
2. Lift the clear plastic vent tube into the sampler controller box. Using a 1/2-inch open end wrench, unscrew the hex
nut at the top of the valve coil. (Note that the tubing will contact the back wall, but by folding it over, the nut can
be removed). This will release the valve coil from the valve body.
3. Remove the large aluminum locking ring that holds the air regulator in place. Carefully loosen it with pliers. The
regulator and lower valve body can be removed from the bottom of the enclosure. Further disassembly now can
be done as required
4. Remove the DC solenoid coil by disconnecting the two spade terminal lead wires and pressing the coil up out of
the grommet. The coil may be tested with an ohmmeter. A good coil will have about 20 ohms resistance. A much
higher resistance indicates an open or burned-out coil, while a much lower resistance indicates a shorted coil.
5. Replace the malfunctioning component and reassemble in reverse order of above steps. Refer to the circuit
diagram for reconnection of solenoid lead wires. Refer to the air pressure regulator adjustment section of this
manual for adjustment of the air pressure regulator.

ISOLOK MSA Sampler 17
Standard Warranty
Sentry Equipment Corp (“Seller”) warrants products manufactured by it and supplied hereunder (“Products”) to be free
from defects in workmanship and, to the extent materials are selected by Seller, to be free from defects in materials, in
each case for a period as dened in the table below:
Product Line Product Category Warranty Period
Sentry® 1. Automatic Sampling
2. Corrosion Monitoring
3. Manual Sampling
4. Sample Conditioning
5. Sampling & Analysis Systems
6. Replacement Parts (without expiration dates)
Eighteen months from date of shipment
or twelve months from startup, whichever
occurs rst
Waters Equipment 1. Sampling & Analysis Systems
2. Replacement Parts (without expiration dates)
Twelve months from date of shipment
To view the full warranty, go to
www.sentry-equip.com/warranty.
Customer Support
With proven sampling expertise since 1924, Sentry products and services provide business operations the critical
insights to optimize process control and product quality. We deliver true representative sampling and analysis
techniques to customers around the globe, empowering them to accurately monitor and measure processes for
improved production eciency, output, and safety. Standing behind our commitments, we are determined to tackle
any application, anywhere.
We know that running an ecient operation isn’t easy. It requires thorough, careful analysis of controlled, real-
time data achieved through reliable, accurate, and repeatable process monitoring, and measuring. By eectively
conditioning, sampling, and measuring gas, liquid, slurry, powder, solids, steam, or water within their production
environments, our customers obtain the critical insights they need to control and optimize their processes.
Yet, controlling your processes also means reliable customer support throughout the life cycle of your equipment.

Customer Service—General information, warranty claims, order management.

Installation Service—For systems that require specialized expertise upon installation.

Technical Support—Troubleshooting, training, and technical manuals.

Field Service & Retrots—When a problem needs immediate attention.

Replacements Parts & Consumables—Order your replacement parts and consumables.
Sentry ProShield Services—Select from four ProShield Guardian service plans providing dierent levels of support to
protect your large system investments with regularly scheduled maintenance.
To learn more, go to
www.sentry-equip.com/support.

18 Sentry Equipment Corp
Appendix: Installation & Operation on a Milk Truck
Sampler and Controller Installation
Please see the “Installation” section of this manual for general installation and sampler controller installation
instructions.
When selecting a location on a milk truck, a typical location is on the ceiling or side wall of the motor compartment, as
close to the sampler location as possible. Otherwise, follow the general controller installation instructions.
Electrical Power Connection
Please see page 10 of this manual for general electrical power connection. The following is specic to power
connection on a milk truck.
This parts package is used with a 12 volt power supply. Install this electrical supply using the following steps:
1. Attach insulated, stranded wire (No. 18 AWG or larger) to a non-switched terminal, such as a non-grounded battery
terminal or equivalent.
2. Run wire lead to the 1/4 in spade-type terminal [+] on back of the cycle controller. Route wire along chassis to give
it protection from accidental damage.
3. Semi-trailer units will require a disconnect between the tractor and trailer. If the existing disconnect has an unused
pin, run the power lead through this pin. Alternately, if two pins are used for similar circuits (e.g., left clearance
lights on one pin, right side on another), consider combining both into one connection and using the remaining
pin for the sampler power lead.
AC Power Supply Package
This parts package is used with 230 VAC supply and recties and transforms 230 VAC to 12 VDC (at 1/2 amp) to supply
the sampler controller. Interlocking to 230 VAC electrical service also automates the “start-stop”sampling function.
Disconnect any 230 volt power supply from the truck before making any electrical connections.
Install the AC electrical supply using the following steps:
1. Locate the power supply in an equipment cabinet convenient to both the sampler controller and pump motor
reversing switch. The power connection is a 36-inch length of exible SJO cord, complete with metallic tting and
conduit lock-nut.
2. Mount the power supply using two brackets attached, or remove the cover to locate mounting holes within the
enclosure using your drawing as a template. Drill holes to accept fasteners selected and secure the power supply
enclosure.
3. Examine the motor conduit box or motor drum switch. The power cord tting is mounted through a 1/2-inch
conduit knock-out. If none can be found, a 7/8-inch diameter hole can be drilled or punched through the conduit
box or drum switch cover, whichever allows a clean mounting of the power supply connector without becoming
an obstruction.
4. Insert the wires and cord connector through the hole and place a conduit nut on the tting, locking rmly.
PROVIDE A SUITABLE GROUND CONNECTION TO POWER SUPPLY. Check ground continuity after mounting.

ISOLOK MSA Sampler 19
5. The sampler controller may be wired to operate the sampler whenever the pump is running, or to cycle the
sampler only when the pump is running in the loading direction. Where the truck pump is used to unload milk
or to discharge cleaning solution, it may be useful to operate the sampler whenever the pump is running. The
ISOLOK MSA sampler can be used to sample an entire truck load, and the sampler will be partially sanitized during
cleaning solution discharge.
6. BIDIRECTIONAL OPERATION is accomplished by splicing two wires (black/white) from the power supply directly
across the motor leads (i.e., in parallel with motor leads T1 and T4).
7. SINGLE DIRECTION OPERATION (loading only) is obtained by wiring two leads (black/white) from the power supply
to one of the following motor lead combinations:
MOTOR CLOCKWISE ROTATION - Connect to T4 and T5 (or) to T4 and T8
MOTOR CCW ROTATION - Connect to T4 and T5 (or) T1 and T8.
8. Make certain that all connections are secure and that splices are properly insulated. Close the drum switch and
motor junction box before connecting the power.
9. Connect the 12VDC output of the AC power supply to the sampler controller using wire with female push-on
connectors on both ends. Plug one end into the 1/4-inch spade receptacle located on the power supply and the
other end into the identical receptacle in the back of the sampler controller. Check for ground continuity between
the power supply module and sampler controller box. Route the wire to protect it from damage or vibration.
ÂNOTE
Within the motor junction box, either T5 or T8 normally will be connected to T2 and T3. Select a combination of motor leads
so that the sampler is NOT wired into this connection.
Polarity
The 12VDC output from the AC power supply is positive. The controller is wired for operation on“hot” positive with
negative to ground. If the sampler controller does not cycle when 230 VAC is ON to the power supply, check the
ground continuity from the power supply base to the compartment wall. Also, check connections on the wire lead
from the power supply to the sampler controller box.
Air Supply Connection
A source of compressed air is required at 50 psi (344 KPa) minimum, up to 120 psi (827 KPa) maximum. The air supply
and piping selected should be capable of providing up to 1 cubic foot of air per minute of sampler operation. The air
supply should be reasonably clean and free of water.
ÂNOTE
Route air line inside dry compartment away from interference with belts, pulleys or other equipment that could cause
damage. Always use exible tubing inside the dry compartment to isolate the sampler controller from the weight and
vibration of hard metal piping.
This air supply can be obtained from one of two alternate sources:
1. TRUCKS WITH AIR BRAKE SYSTEMS: The small amount of air needed for sampler operation usually can be taken
from the air reservoir of the vehicle. If an air supply package has been selected with the sampler system, it includes
air tubing and commonly needed ttings. Alternately, tubing and ttings can be obtained locally.
a. Examine the air brake reservoir tank(s) and locate a connection point near the top of the tank, high enough to
prevent accumulated moisture or water from owing into the supply line.

20 Sentry Equipment Corp
b. Use appropriate ttings to attach a 1/4-inch supply line to the tank. Install an air shut-o valve on the tank or
at a location convenient to the driver to permit the air supply to be easily turned o for safety purposes or as
other conditions require.
c. An automatic shut-o valve also is recommended in the air line near the tank. This valve acts as a circuit
breaker, automatically shutting o air ow if the supply line is accidentally broken between the valve and the
sampler. Government regulations or plant safety codes often require this valve. Select a valve with sucient
ow capacity to operate the sampler at its maximum cycle rate.
d. Use a 1/4-inch bulkhead tting, provided with the sampler package, to penetrate a dry compartment wall. Drill
a 3/8-inch hole through the wall, insert the bulkhead tting and tighten securely with locking nuts.
e. Run a 1/4-inch OD tube from the shut-o valve to the bulkhead tting connection on the outside of the dry
compartment. Use 1/4-inch OD copper or other approved metal tubing. Support and protect the tubing along
the truck chassis to prevent damage from road conditions or vibration. Tighten all connections securely.
f. Inside the dry compartment, run 1/4-inch OD exible plastic tubing, provided with sampler package, from
interior bulkhead tting to the 1/4-inch tube tting on the left side of the sampler controller (regulator input).
Tighten compression ttings securely.
2. TRUCKS WITHOUT AIR SUPPLY: Where trucks use hydraulic brakes, or other conditions prevent connecting to an
on-board air supply, a small air receiver tank can be installed to operate the sampler. An appropriate tank size is 6
to 12 gallon capacity, and it should be code rated (U.S. Dept. of Transportation or equal) for service to at least 120
psi (827 KPa). Tanks can be obtained locally from rms that build or repair truck air brake systems, or an air tank
package is available from Sentry Equipment Corp. A typical supplier is Bendix/Westinghouse.
A typical 7-1/2 gallon air reservoir (part of the air tank package), charged to 120 psi, will provide approximately
2000 sampler cycles before recharging. At 0.5 cc of sample per cycle, this equals one liter of sample, or
approximately 25 samples of 40cc quantity each.
INSTALLATION:
a. Determine an appropriate location on the truck for the air reservoir. It should be protected from road damage,
but accessible for recharging with compressed air.
b. Ensure that the air tank is equipped with a water blow-o valve at its lowest point. Also supply an air inlet (tire-
valve tting or equal). Both are provided with the Sentry air tank package.
c. Pipe the air outlet from the top or end of the tank with ttings to attach a 1/4-inch OD supply line. A shut-o
valve in the supply line is recommended. Complete the installation in same manner as outlined for trucks with
air brake systems.
Typical Operation Procedure
Following is a typical milk pickup sequence using the ISOLOK MSA sampler. Steps not covered should be carried out in
accordance with standard methods as prescribed by local, state or other health regulatory agencies.
1. The ON-OFF switch remains “on”continuously when the AC power supply package is installed. Starting and
stopping the sampler usually is controlled by switching the power to the pump motor on or o. Use the ON-OFF
switch to start and stop sampler operation when power for the sampler controller comes directly a truck electrical
system (DC power supply package or equivalent installation). Turn the switch o when sampler operation is not
desired.
2. Ensure the compressed air supply is ON.
3. Attach the sample container (bottle, bag or vial) to the sampler.