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Sampling Systems Handbook

and Approval Guide

Last revision: February 21, 2012 CGC Industry Services ISO 9001:2008 Services lindustrie CCG


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Table of Cont ents

Chapt er 4 ....................... ........................ ............ 1Types of samp ling syst ems4.1 ..........................................1Sampling systems that are eligible for approval

4.2 ...................................................................2Arc-path cross-stream samplers4.3

...................................................................................4

Conditionally approved automatic samplers (non-conforming and

previously approved)

4.4 .................................................................................................8Intended use4.5 ........................................................................................................8Marking

4.6 ................................................................................................8Repeatability

4.7 ..........................................................................................8Speed of traverse4.8 ................................................................9Power, air, and hydraulic sources

4.9 ........................................................................................................9Controls

4.10 ....................................................................................9Enclosure and access4.11 ...........................................................................9Sample collector openings

4.12 .............................................................................................10Sample return

4.13 .................................................................................11Sample delivery lines

4.14 .............................................................................12Sampler delivery access4.15 .................................................................................12Clearing between lots

Please direct any comments, questions or concerns regarding the contents of this manual

or any proposed revisions or suggestions to:

Chief Grain Inspector for Canada

Canadian Grain Commission

900-303 Main St

Winnipeg, ManitobaR3C 3G8

Phone (204) 983-2780 Fax (204) 983-7550Contact Us - Canadian Grain Commission
http://www.grainscanada.gc.ca/contact-contact/contact-eng.htmhttp://www.grainscanada.gc.ca/contact-contact/contact-eng.htmhttp://www.grainscanada.gc.ca/contact-contact/contact-eng.htm


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Chapter 4 Types of sampling systems4.1 Sampling systems that are eligible for approvalIn general, the CGC will give approval only to sampling systems that extract a complete

and proportional cross-section of the grain stream (both height and width), proportionallyreduce the sample size, and deliver the sample to the inspection area. (Exceptions are

discussed in Section 4.3.) Samplers of this type are commonly referred to as cross-stream

diverter-type samplers (see Figure 4.1). The dividers and the delivery system mustconform to manufacturer specifications and must be constructed of the industrial

durability required to operate in the environment where the system is located.

CGC approval for any new sampling concepts will be based on the ability of the

proposed sampling system to extract a two dimensional (height and width) section of thegrain stream, proportionally reduce the sample size, and deliver the sample to the

inspection area.

Figure 4.1: Cross-stream sampling

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4.2 Arc-path cross-stream samplersAn arc-path cross-stream sampler is defined as sampler where the cutter rotates from a

centre point and traverses the grain stream by following an arced path. These may be

eitherflowing stream samplers orfalling stream samplers (see Figures 4.2 and 4.3).

Figure 4.2: Arc-path cross-stream samplerflowing stream

Figure 4.3: Arc-path cross-stream samplerfalling stream

Arc-path samplers may be approved for official inspection purposes, provided that the

cutter opening exposes a minimum of 1.9 cm ( (0.75) inch), measured perpendicular to

the grain stream, as the cutter enters and exits the grain stream (see Figure 4.4).

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Figure 4.4: Cutter opening requirement for arc-path cross-stream samplers

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4.3 Conditionally approved automatic samplers (non-conformingand previously approved)

Woodside samplers (Figure 4.5) strip/auger samplers (Figure 4.6) or point type samplers(Figure 4.7) that were previously approved by the CGC are non-conforming to these

requirements and are no longer authorized to collect samples for official CGC certication

of vessels and railcars. These types of samplers may be considered conditionallyapproved if certain criteria are met.

At the discretion of the CGC, a non-conforming sampling system may be used to sample

grain

(1) during a weigh-over provided that the sampling system is under the direct supervision

of the CGC.(2) by the CGC, by 3rd party staff accredited by the CGC or by grain company staff

certified by the CGC provided that:

a) the sampled grain, either bulk or bagged is destined for shipment in a container,b) the sampling system has been reviewed and authorized by the CGC, and

c) the sampling system is used and maintained in the manner deemed suitable by theCGC.

The following criteria will be used by the CGC in reviewing and authorizing samplingsystems:

- The sampling tube may be either installed permanently in the grain stream or the tubemay extend into the grain steam intermittently.

- Where the sampling tube extends into the grain, the tube must extend to at least 75%of diameter of the grain stream.

- The combined length of the sampler tube opening on the sampling tube must be atleast 55% of the probe length,

- One sampling tube opening must be within of an inch of the spout wall where theproduct is flowing.

- The dimensions of the sampling tube openings must be at least of an inch wide and3 inches long and be in a uniform pattern along the entire length of the tube.

- Automatic samplers must have an adjustable timer. Sampler timers may be eitheranalog or digital, and must have a maximum 1-second dial or timer interval setting.

- Sampling intervals will be determined on a case by case basis, to ensure adequatesampling intensities and frequencies are being achieved.

Note: any deviations from these criteria will be considered on a case by case basis.

Some examples of non-conforming (Figure 4.8) automatic samplers are:

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Figure 4.5: Woodside sampler

Figure 4.6: Strip/auger sampler

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Figure 4.7: Point type sampler

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Figure 4.8: Non-conforming automatic samplers

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Sampling systems: general requirements

4.4 Intended useThe design, composition, and construction of a sampling system and its associated

equipment must suit the environment, the installation location, and the intended official

use of the sampling system. The device must be able to withstand normal operationwithin the facility without loss of reliability or accuracy. Under normal operation, any

moving parts must remain operable and any adjustments must remain reasonably

constant.

4.5 MarkingThe primary sampler and associated divider or pneumatic components must be

permanently marked to show the manufacturer, model, and serial numbers. The rated

maximum throughput capacity must also be marked on the device or be readily availablebased on the model number.

4.6 RepeatabilityThe overall dimension of the sample entry and sample cutter must be adequate for the

volume and velocity of the grain being sampled, and must allow:

All grain presented for sampling to be accepted as the collection opening passesthrough the grain stream

The sample cutter to deliver the entire collected sample to the divider for reduction orto the final sample collection site

When collecting official samples:

The rate of grain flow past the sampler should not be less than 25% of the rated

maximum capacity of the grain elevation/conveying system.

All sampling systems installed within an elevator must provide a similar quantity of

sample when used for the same purpose. The quantity of sample delivered must be within10% of any other sampling system when sampling the same type and quantity of grain.

4.7 Speed of traverseAny non-programmable speed setting must be set to maximize the efficiency andeffectiveness of the sampling system. The traverse speed of the sample cutter across the

grain stream must be set at 0.47 0.51 metre per second (18 20 inches per second) and

at an even rate of acceleration.

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4.8 Power, air, and hydraulic sourcesElectrical power sources for the operation of a sampler and any associated equipment

must be maintained at a constant voltage to ensure the smooth and unaffected operation

of the equipment.

Air or hydraulic sources for the operation of a sampler and any associated equipmentmust be maintained at a constant and uniform pressure to ensure the smooth and

unaffected operation of the equipment. If the operation of any equipment attached to the

same air or hydraulic supply affects the operation of the sampling system, a separate airor hydraulic supply will be required.

4.9 ControlsDuring the operation of a sampling system for official inspections, the control of the

timer and resets must be under the direction of the CGC staff on site or be readilyavailable to them. If a grain flow indicator is required to verify grain flow rates, it must

be made available. Equipment controls must be marked conspicuously and be within

viewing range of the CGC staff.

4.10 Enclosure and accessAll sampling components must be maintained within protective enclosures. The sampling

system must have strategically located access points for inspections. The locations mustallow for ready and easy examination of the sampler components, including the sample

cutter openings, motion activation equipment, and dust seals.

4.11 Sample collector openingsThe opening of a sampler cutter must be at least 1.9 cm ( (0.75) inch) wide, measured

horizontally to the grain stream (see Figure 5.1). The opening may be reinforced withnarrow support braces to provide structural support and eliminate any distortions to the

opening.

A gravity or automatic sample divider must be adequately sized to reduce the quantity ofsample from the primary sampler without backing up. Sample divider openings used to

select the final sample must be at least 1.9 cm ( (0.75) inch) measured horizontally to

the primary sampled grain stream.

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Figure 5.1: Sampler cutter/braces

4.12 Sample returnWhere the sampler system is installed downstream of a weighing system in a shipping

installation or upstream of a weighing system in a receiving installation, means must beprovided to return the surplus sample back to the source grain lot. Where miniature

bucket elevators, screw conveyers, or drag conveyers are used to move the surplus

sample, they must be adequately sized to prevent a backlog of grain in the system.

Either the return line for the sample must be to a neutral air pressure location, orautomatic means must be in place to prevent any dust or lightweight material from being

pressured back into the sample divider or from being vacuumed or vented out of the

sample divider.

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4.13 Sample delivery linesSample delivery lines from the sample divider to the inspection area must follow the most

direct route to the inspection area with as few bends as possible (see Figure 5.2). In

particular:

Delivery lines must not have a turn radius greater 90 degrees and must be laidvertically or horizontally as much as possible.

The delivery conduit must be cut squarely and the inside edges honed to remove anyroughness or burrs.

Conduit for negative or positive pressures must be connected with an airtightcoupling.

An electrical path must be maintained over the entire delivery system with suitablegrounding points to discharge any static build up. (It is recommended that sample

delivery lines be of metal conduit construction, aluminum straight pipe, and stainlesssteel elbows.)

The air intake on pneumatic systems must be equipped with a suitable cover to stopunwanted material from being introduced into the official sample. The cover must be

removable to allow for inspection and any necessary testing.

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Figure 5.2: Delivery lines for samples

4.14 Sampler delivery accessA sampler delivery system must have an access point as close to the primary sampler as

possible and after any sample divider, to allow the CGC to introduce CGC drop samples.

4.15 Clearing between lotsThe entire sampling system must be as self-clearing as possible to prevent sample

contamination from one lot of grain to another.

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