Sampling Systems Handbook and Approval Guide

2. Automatic sampling systems for licensed grain handling facilities

2.1 Overview

Automatic sampling systems used to collect samples for inspection purposes at licensed grain handling facilities must meet the requirements as defined in this Sampling Handbook.

In general, the Canadian Grain Commission will give approval only to automatic sampling systems that extract a complete and proportional cross-section of the grain stream (both height and width), proportionally reduce the sample size, and deliver the sample to the inspection area. Samplers of this type are commonly referred to as cross-stream diverter-type samplers. The dividers and the delivery system must conform to manufacturer specifications and must be constructed of the industrial durability required to operate in the environment where the system is located.

The Canadian Grain Commission must retain operational control or have access to the operational control of automatic sampling systems and the authority to accept or reject the use of those devices. As proprietors of the sampling systems, grain handling facilities must be aware of their responsibilities to obtain and maintain Canadian Grain Commission approval of their sampling systems.

2.2 Equipment requirements

Canadian Grain Commission 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 the grain stream, proportionally reduce the sample size, and deliver the sample to the inspection area.

Arc-path samplers may be approved for official inspection purposes, provided that the cutter opening exposes a minimum of 1.9 cm (0.75 inches), measured perpendicular to the grain stream, as the cutter enters and exits the grain stream.

Diagram showing cutter opening requirement for arc-path cross-stream samplers. Description below.

Cutter opening requirement for arc-path cross-stream samplers. The line drawing is showing the cutter opening measuring at least 1.9 cm (0.75 inches) as it enters the grain stream, when it is at the centre of the grain stream, and as it exits the grain stream.

Front view of cutter – belt end

Diagram of a cross-stream sampler cutter path. Description below.

Cross-stream sampler cutter path. The line drawing is showing the requirements for sampling using a cross-stream sampler. The diagram shows the sampler cutter trajectory and direction, and illustrates both a correct sample increment and an incorrect sample increment. The diagram shows that the width of the increment must be the same, regardless of where it is taken in the grain flow.

Arc-path cross-stream samplers

An arc-path cross-stream sampler is defined as a sampler where the cutter rotates from a centre point and traverses the grain stream by following an arced path. These may be either flowing stream samplers or falling stream samplers.

Diagram of the flowing stream of an arc-path cross-stream sampler. Description below.

Flowing stream. The line drawing is showing a top view and a side view of the flowing stream type of arc-path cross-stream sampler. The diagram shows the direction of the grain stream, the sampler cutter trajectory, and the direction of the increment sample.

Diagram of the falling stream of an arc-path cross-stream sampler. Description below.

Falling stream. The line drawing is showing a top view and a side view of the falling stream type of arc-path cross-stream sampler. The diagram shows the direction of the grain stream, the sampler cutter trajectory, and the direction of the increment sample.

2.210 Intended use

The design, composition, and construction of a sampling system and its associated equipment must suit the environment, the installation location, and the intended use of the sampling system. The device must be able to withstand normal operation within the facility without loss of reliability or accuracy. Under normal operation, any moving parts must remain operable and any adjustments must remain reasonably constant.

2.211 Marking

The 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 available based on the model number.

2.212 Repeatability

The 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:

  1. All grain presented for sampling to be accepted as the collection opening passes through the grain stream
  2. The sample cutter to deliver the entire collected sample to the divider for reduction or to the final sample collection site

When collecting 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 a licensed grain handling facility must provide a similar quantity of sample when used for the same purpose. The quantity of sample delivered must be within 10% of any other sampling system when sampling the same type and quantity of grain.

2.213 Speed of traverse

Any non-programmable speed setting must be set to maximize the efficiency and effectiveness 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.

2.214 Power, air, and hydraulic sources

Electrical 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 equipment must 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 air or hydraulic supply will be required.

2.215 Controls

During the operation of a sampling system for official inspection, the control of the timer and resets must be under the direction of the Canadian Grain Commission staff on site or be readily available 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 Canadian Grain Commission staff.

2.216 Enclosure and access

All sampling components must be maintained within protective enclosures. The sampling system must have strategically located access points for inspections. The locations must allow for ready and easy examination of the sampler components, including the sample cutter openings, motion activation equipment, and dust seals.

2.217 Sample collector openings

The opening of a sampler cutter must be at least 1.9 cm (0.75 inches) wide, measured horizontally to the grain stream. The opening may be reinforced with narrow support braces to provide structural support and eliminate any distortions to the opening.

Diagram of a reinforced sampler cutter. Described below.

The line drawing is showing a sampler cutter in which the opening is reinforced with narrow support braces. The diagram shows the direction of grain stream and increment sample.

2.218 Surplus sample return

Where the sampler system is installed after a weighing system in a shipping installation or before a weighing system in a receiving installation, means must be provided 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.

The return line for the surplus sample must be to a neutral air pressure location, or automatic means must be in place to prevent any dust or lightweight material from being pressured back into, or vented out of, the sample divider delivery system.

2.219 Sample delivery lines

Sample 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. In particular:

  1. Delivery lines must not have a turn radius greater 90 degrees and must be laid vertically or horizontally as much as possible.
  2. The delivery conduit must be cut squarely and the inside edges honed to remove any roughness or burrs.
  3. Conduit for negative or positive pressures must be connected with an airtight coupling.
  4. An electrical path must be maintained over the entire delivery system with suitable grounding points to discharge any static build up. (It is recommended that sample delivery lines be of metal conduit construction, aluminum straight pipe, and stainless steel elbows.)
  5. The air intake on pneumatic systems must be equipped with a suitable cover to stop unwanted material from being introduced into the official sample. The cover must be designed to accommodate security seals and also removable to allow for inspection and any necessary testing as required.

2.220 Sample delivery system access

A sample delivery system must have access point(s) as close to the primary sampler as possible and after any sample divider. This requirement is to allow for the introduction of Canadian Grain Commission control samples which are used to aid in the determination of the overall effectiveness of the sample delivery line(s). These access points must have means to provide security seals.

2.221 Clearing between lots

The entire sampling system, including delivery lines, must be self-clearing to prevent sample contamination from one lot of grain to another while in use.

2.222 Location and installation

The location selected for a proposed sampling system must meet the requirements of the Canadian Grain Commission. Any nearby equipment must not adversely affect the operation of the sampler or delay its operation in any manner. Lighting in the area of the sampler must be sufficiently intense (approximately 100 lux) and preferably permanently installed in order to allow the visual inspections of the sampling system.

Diagram of the configuration of a basic automatic sampling system. Description below.

Basic Automatic Sampling System Configuration. The line drawing is showing the path a sample takes from the sampler through to the sample collector (Koster valve). The diagram includes an expanded schematic of a Morris coupler. Morris couplers are used at various points along the delivery lines.

2.223 Segregation of samples

This section describes where to locate samplers and segregate samples in such a way as to ensure that the sample is representative of the grain lot.

  1. On inward (receiving) sampling systems, the sampler must be located before or immediately after the initial elevation. The sample is considered representative only after the entire lot of grain being sampled has passed by the sampler and had the opportunity to be sampled.
  2. On outward (shipping) sampling systems, the sampler must be located after the final elevation and as close as practical to the end of the loading spout. The sample is considered representative only after the entire lot of grain being sampled has passed the sampler and had the opportunity to be sampled.
  3. Samplers located in spouts must not come after a vertical drop of more than 15 metres or be within 0.6 metre of any bends in the spouting.
  4. Before sampling grain to railcars, the sample delivery system must be purged with the same grain and similar quality. The purge must be to the furthest return-to-house point in the shipping system. The grain delivery system must also be purged in the same way if the elevator operator changes the grain or grade to be sampled.
  5. Outward samplers used for loading railcars must be installed or operate in such a way that the railcar into which the sampled grain is loaded can be identified for each sample.
  6. Where the sampler is located above the weighing system, or below the scale but before shipping or pre-weigh bins, there must be automated means available for Canadian Grain Commission staff, such as bin or hopper empty sensors, to identify that the grain being sampled has been delivered to the intended conveyance.

2.224 Divider installation

The divider associated with a sampler must be installed in accordance with the manufacturer’s specifications and be reasonably close to the primary sampler. A gravity or mechanical sample divider must be adequately sized to reduce the quantity of sample from the primary sampler without causing the grain to potentially plug the sample delivery system and therefore impact the integrity of the sample. Sample divider openings used to select the final sample must be at least 1.9 cm (0.75 inches) measured horizontally to the sampled grain stream.

The divider installation site must be free of hazards, have adequate space for inspecting the device, and be sufficiently clean from dust, spilled grain, and refuse. Lighting in the area of the divider must be sufficiently intense (approximately 100 lux) and preferably permanently installed. Dividers may be of the swing arm type, rotary type or gravity type.

Diagrams of a swing arm divider and a rotary divider. Description below.

The line drawing is showing a swing arm divider and a rotary divider. In both diagrams the path of the increment sample and the path of the surplus sample are shown.

2.225 Timer installation and use

Sampler timers may be either analog or digital, and must have a maximum 1-second dial or timer interval setting. A sampler timer must be accurate to within ±1 second of the cycle time.

At licensed grain handling facilities where the timers reside in the programmable logic controller (PLC), access to the programming must be made available on request. The facility must bring any adjustment to the timing of the sampler to the attention of CGC personnel prior to making any change.

When loading or unloading railcars or trucks, the timer of a cross-stream sampler must be set to an interval not greater than 20 seconds. The divider reduction rate and the sampler timer interval must be set to collect a sample quantity representing between 0.0025 percent and 0.0075 percent of the lot being sampled. For example; on a 90 tonne railcar, between 2.25-6.75 kg of sample must be collected.

When loading or unloading vessels or barges, the timer of a cross-stream sampler must be set to an interval not greater than 45 seconds. The divider reduction rate and the sampler timer interval must be set to collect a sample quantity representing between 0.0005 percent and 0.001 percent of the lot being sampled. For example; on a 2000 tonne increment, between 10 to 20 kg of sample must be collected.

When loading railcars where the sampler is below the weighing system, it is permitted to interlock the sampler with a scale draft counter if the following is met:

Where the draft of the bulk weighing system is less than 8 tonnes, the sampler may be timed to traverse at approximately the middle of the draft discharge or it may traverse at a random interval during the discharge. The random interval must not be controlled by an operator and must ensure that the sampler traverses during the period when grain is flowing.

It is also acceptable to have the sampler traverse the grain stream based on the time during which grain is actually flowing past the sampler in a spout. To accomplish this, a flow detector is installed immediately before or after the sampler and is integrated with the sampler control. The flow sensor activates the sample interval timer when product is flowing in the spout and stops the time when there is no flow. When flow is detected again, the interval timer resumes from the point where it stopped.

For example, if the sample interval is 20 seconds and flow stops when the elapsed time since the sampler last traversed is 16 seconds, the sampler traverses when flow has resumed for 4 seconds.

2.226 Blending limitations

Any blending of grain must be completed in an even and uniform manner prior to the grain reaching the sampler.

2.227 Integrity of grain lots

Means must be provided to prevent the addition of grain or other commodities to the grain stream, or the removal of any portion of the sampled grain, after it has passed the sampler. Feeder spouts or diversion spouts after the sampler must be sealable with Canadian Grain Commission security seals, keyed locks, or positive electronic means under the direction of the Canadian Grain Commission personnel. If, during official Canadian Grain Commission inspections, security means are found to be missing or to have been tampered with, the shipment or lot will be rendered non-representative.

The sampling, weighing, and delivery systems must not be manipulated, operated, or circumvented in any manner intended to purposefully influence, degrade, or bias the sample, any part of the sample, or the lot of grain the sample represents.

2.3 Verification and approval process

Prior to being approved for use, any new or modified sampling unit must be examined by Canadian Grain Commission personnel.

Before requesting Canadian Grain Commission approval, the licensed grain handling facility should compare belt samples or spout samples (obtained using standard manual sampling methods or an acceptable alternative) with the mechanically obtained sample from the same lot, in order to prove likeness and quality preservation through the system. They should also evaluate the delivery lines to ensure they are operating in accordance with the conditions outlined in this Sampling Handbook.

Before granting approval, Canadian Grain Commission Industry Services personnel will examine the sampling system to confirm all the requirements outlined in this Sampling Handbook are satisfied. This evaluation is comprised of a series of three steps, all of which need to be completed in their entirety prior to approval being granted. Canadian Grain Commission personnel will coordinate the timing of this process with the licensed grain handling facility management.

Licensed grain handling facility staff will be required to give access, and assist in any evaluations as determined by Canadian Grain Commission personnel. Results of any testing conducted will be made available to facility management upon request.

Step 1: Complete a Sampler Condition and Efficiency Check. This process involves examining all the sampling equipment to ensure the installation meets the requirements as per manufacturers’ specifications and those identified in this Sampling Handbook.

Step 2: Complete a Delivery System Evaluation. This process requires that three samples of known quality and quantity per grain group be introduced into the delivery system as close to the primary sampler as possible. These samples are collected and analysed for quantity and quality. A total of six samples are used to evaluate the effective operation of the delivery system. The results of this test are analysed and used to identify any potential areas of concern in the operation of the delivery system. It is at the discretion of the Canadian Grain Commission to accept or reject the results of this process.

Step 3: Complete an Operational Verification. This process consists of a visual and operational confirmation that the entire sampling system operates as expected, and delivers a sample conforming to the requirements of this Sampling Handbook over a period of time to be determined by Canadian Grain Commission personnel. The operational verification may also include a comparison to manually obtained samples; or to samples obtained by another automatic sampler to ensure the sample resembles the properties of the grain being sampled.

Sampling systems must meet all the examination requirements described above in order to be approved for use by the Canadian Grain Commission. Basis the results of these evaluations, the Canadian Grain Commission will issue a letter of notification to the licensed grain handling facility indicating the status of the sampling system. Results of any testing conducted by Canadian Grain Commission personnel will be made available to the grain handling facility management upon request.

2.4 Security of sampling system

Means must be provided to apply Canadian Grain Commission security seals to any access points as determined by Canadian Grain Commission personnel. For example; on inspection doors located on the sampler and divider, or on certain sample delivery line access points to ensure the integrity of the system is maintained and verifiable as deemed necessary. When any security seals are breached by licensed grain handling facility staff as a result of maintenance, or any other cause, Canadian Grain Commission personnel must be notified immediately so that security seals may be reapplied and documented as required. Any security seals found not to be intact may result in a temporary suspension of the sampling system until the details of the security seal breach can be investigated.

2.5 Maintenance

It is the responsibility of the licensed grain handling facility to install and maintain all Canadian Grain Commission approved sampling systems as prescribed by the manufacturer and in accordance with this Sampling Handbook. Facility management must provide all necessary repairs, maintenance, and environmental considerations specified by Canadian Grain Commission personnel and the manufacturer. When alterations to the system are planned, or unexpectedly arise, facility staff must notify Canadian Grain Commission personnel and provide written details prior to initiating any change to the system. Facility staff is responsible to keep a “maintenance log” on each Canadian Grain Commission approved sampling system, to be made available for review on request. Any ongoing sampling system problems that are being experienced by the grain handling facility operators are to be reported to Canadian Grain Commission personnel. Any Canadian Grain Commission security seals that are breached when performing any maintenance function must be reported immediately. When any alterations are made to any sampling system or components thereof, the Canadian Grain Commission may require the system to be re-evaluated to ensure its continued compliance to this Sampling Handbook. At the discretion of the Canadian Grain Commission, this may require a detailed evaluation of the entire system.

2.6 Monitoring and oversight

The Canadian Grain Commission approves and oversees the operation of all automatic sampling systems used to draw samples on outward discharge at licensed terminal grain handling facilities. In addition, the Canadian Grain Commission’s responsibilities include an oversight role for inward sampler and delivery systems used for receipt of grain at licensed terminal elevators. These systems will be subject to regular monitoring and oversight protocols established by the Canadian Grain Commission. The protocols for automatic sampling systems used to collect these samples will be determined upon the sampling systems’ installation location and use within each licensed grain handling facility. The monitoring and oversight protocols for Canadian Grain Commission approved automatic samplers used for inward receipt and outward discharge from licensed terminals are as follows:

Inward receipt into licensed terminal elevators

On a 3 month cycle, Canadian Grain Commission personnel will conduct an in-depth visual monitoring and oversight inspection. This will include, but not be limited to, visually checking the entire system for any leaks, diversions or security seal breaches. Equipment will be verified, and the general condition and operation will be determined to ensure that the sampling system is being operated and maintained as described in this Sampling Handbook. Facility sampling system maintenance records will be reviewed if/when required.

On a 12 month cycle, Canadian Grain Commission personnel will conduct a complete “Verification and Approval Process” (see section 2.3) of the entire sampling system to ensure its continued conformance to the requirements outlined in this Sampling Handbook.

Sampling systems that are considered by the Canadian Grain Commission to be in use “seasonally” will be evaluated prior to the beginning of each season. The requirements for Canadian Grain Commission approved automatic sampling systems that are only used “occasionally” will be determined on a case by case basis.

Note: At the discretion of the Canadian Grain Commission, any approved sampling system that is suspected to be operating with questionable accuracy may be subject to an in-depth review prior to the 12 month anniversary review period.

Any system found not to be in compliance with this Sampling Handbook will result in written notification to the licensed terminal elevator operator indicating that remedial action is required. This notice will include details of non-compliance issues and an expected timeframe that facility management have to address the non-compliance(s).

Outward discharge from a licensed terminal elevator

Each shift (when outward discharge to a vessel is occurring), Canadian Grain Commission personnel onsite will inspect and monitor the sampling system to ensure it is operating as expected.

On a 3 month cycle, Canadian Grain Commission personnel will conduct an in-depth visual monitoring and oversight inspection. This will include, but not be limited to, visually checking the entire system for any leaks, diversions or security seal breaches. Equipment will be verified, and the general condition and operation will be determined to ensure that the sampling system is being operated and maintained as described in this Sampling Handbook. Facility sampling system maintenance records will be reviewed if/when required.

On a 36 month cycle, the Canadian Grain Commission will conduct a complete “Verification and Approval Process” (see section 2.3) of the entire sampling system to ensure its continued conformance to the requirements outlined in this Sampling Handbook.

Sampling Systems that are considered by the Canadian Grain Commission to be in use “seasonally” will be evaluated prior to the beginning of each season. The requirements for Canadian Grain Commission approved automatic sampling systems that are only used “occasionally” will be determined on a case by case basis

Note: At the discretion of the Canadian Grain Commission, any approved sampling system that is suspected to be operating with questionable accuracy may be subject to an in-depth review prior to the 36 month anniversary period.

Any system found not to be in compliance with this Sampling Handbook will result in written notification to the licensed terminal elevator operator indicating that remedial action is required. This notice will include an expected timeframe that facility management have to address the non-compliance(s).