PAUT Channel Counts: Read 16:64 and 32:128 Before Buying
A phased-array label such as 16:64 contains two different capacity numbers. Understand what each means for the manufacturer’s architecture, then evaluate the actual probe, software and inspection requirement before paying for more channels.
For: U.S. NDT equipment coordinators, quality staff and inspection business owners
Read the notation as a defined specification
Evident's phased-array equipment explanation describes the common two-number notation as the maximum elements that can be activated together and the maximum elements that can be connected. Under that convention, 16:64 does not mean that sixty-four elements are all activated together to form one conventional phased-array beam. The two numbers answer different questions. Confirm the supplier's definition for the exact architecture instead of extending one convention blindly to every product label.
Keep a plain-language translation beside each quotation. Record what the first number represents, what the second represents, and any suffix or option that changes the stated capability. This is especially useful when a purchasing team compares listings from different suppliers or used-equipment sellers. A shortened advertisement may omit the information needed to identify the actual configuration, even though the product family name is familiar.
Do not treat the numbers as a procedure. The responsible technical authority determines the probe arrangement and acquisition requirements for an application. Understanding the notation helps purchasing ask whether the proposed instrument supports those requirements; it does not tell an inspector which elements to use, what beam to form or how to establish coverage. This guide supplies no operating settings or universal channel minimum for a particular examination.
Separate probe element count from active capability
A probe's total element count and an instrument's simultaneous active capability are related but distinct. A buyer can see a probe with many elements in a package and mistakenly assume the instrument can use all of them together in every mode. Ask the supplier to explain the supported relationship for the proposed instrument, probe and software. The answer should identify any limitations that affect the approved application rather than merely confirming that the connector fits.
Record the exact probe identity in the capability comparison. A label such as sixty-four-element probe does not describe its complete geometry, connector arrangement or other characteristics relevant to technical suitability. The technical team should supply the controlled probe requirement and determine whether the proposed combination is acceptable. Purchasing then checks the quoted configuration and compatibility evidence against that requirement.
Avoid reducing the choice to a rule that more active elements is always better. The useful capability depends on the approved examination and the complete system. Extra capacity may support a defined future use, or it may add cost without changing the current workflow. The decision should explain which requirement the additional capacity addresses and what evidence supports that conclusion, rather than treating the larger number as a universal quality score.
Compare requirements by acquisition mode
Ask which mode each capability statement applies to. Conventional phased-array beam formation, FMC acquisition, TFM reconstruction and other supported approaches can have different configuration requirements. A number quoted for one mode should not automatically be applied to another. The technical reviewer should identify the relevant modes and required functions, while the supplier confirms the capability of the exact model and enabled options.
Evident's computer-controlled acquisition article provides a concrete example: it describes specific OmniScan X4 configurations for a linked workflow and a particular configuration for raw FMC access. That is evidence that model details can matter beyond a broad family name. It is not a recommendation to buy that configuration or a claim that the same conditions apply to another instrument.
If a future mode is part of the business case, separate current capability from an upgrade path. Ask whether the upgrade is software enabled, requires hardware changes or depends on another system component. Obtain the applicable commercial and technical confirmation from the supplier. A statement that the platform is expandable should not be counted as a presently delivered and demonstrated capability until the required configuration and conditions are clear.
Do not confuse channel capacity with probe count
A multi-probe arrangement introduces questions that a single channel label does not answer. Ask how the proposed system supports the required probes, connectors, switching or simultaneous acquisition under the approved workflow. The technical authority decides what is needed; purchasing should identify the relevant accessories and options in the quotation. One large capacity number does not establish every possible multi-probe arrangement.
List each intended probe and its role in the accepted configuration schedule. Record the connection path and any manufacturer-specified accessory needed to support it. This creates a reviewable package definition without turning the purchasing file into a wiring instruction. If a supplier proposes a splitter or adapter, obtain the appropriate compatibility evidence and technical review before treating it as interchangeable with a direct connection.
Ask the demonstrator to use the proposed arrangement when a demonstration is required. A single-probe demonstration may establish useful instrument behavior but leave the multi-probe requirement unresolved. Keep that boundary explicit in the evidence record. The buyer can then request an additional test or accept a defined limitation without overstating what the first demonstration proved.
Distinguish channels from groups, laws and stored data
Suppliers may describe channel counts alongside groups, focal laws, display views and storage capabilities. These are different specifications. Ask the technical reviewer which ones constrain the approved application and ask the supplier how they interact in the proposed configuration. A high value in one row should not be used as a substitute for an unanswered requirement in another row.
Create separate comparison rows for the required acquisition arrangement, simultaneous or sequential behavior, retained data and review workflow. The exact terms should follow the manufacturer's documentation and the technical team's requirement. This prevents purchasing from comparing unlike values, such as a connected element capacity in one quotation with a software group limit in another. If the meaning of a term is unclear, resolve it before assigning a score.
Include the saved evidence in the demonstration. The instrument may display several views while retaining only the objects supported by the selected workflow. Ask what can be reopened and reviewed after acquisition. The FMC and TFM retention guide addresses that distinction. A channel count does not establish a native file's contents or prove that a customer can perform the intended later analysis.
Translate the approved use into a capability worksheet
Have the technical authority provide a concise statement of the instrument capabilities needed for the current application. Purchasing should organize that statement into rows with the requirement, proposed configuration, evidence reference, reviewer and status. The worksheet is an administrative artifact. It should not create new technical criteria by copying a recommended setup from an unrelated example or product tutorial.
Use evidence states that preserve uncertainty. Included and demonstrated is different from documented but not tested, optional at additional cost or subject to technical confirmation. A supplier can provide useful documentation without having completed your organization's acceptance review. The worksheet should show both facts. This makes the purchasing decision understandable to someone who did not attend the sales discussion.
Keep future applications in a separate portion of the worksheet. For each one, record how definite the need is and what additional capability it would require according to the technical team. A vague possibility of future work should not be presented as a verified technical requirement, but it can be part of an informed commercial decision. The buyer should see which expenditure supports current work and which supports an explicitly uncertain opportunity.
Compare configurations without relying on family names
A product family may be sold in more than one configuration or with different enabled features. Eddyfi's Mantis product information illustrates why buyers should review the model and software context rather than relying on the family label alone. Obtain the current configuration statement for the unit being quoted, especially when the offer concerns a demonstration, rental or previously owned instrument.
Ask for a serial-specific confirmation when the configuration cannot be established from the listing. The seller should identify the relevant hardware and options, while the manufacturer or authorized support channel can clarify questions within its scope. Do not assume that every unit sharing a housing or model family has the same capability. A photograph of the front panel is not a complete configuration record.
At delivery, compare the received unit with the accepted quotation and demonstration evidence. Record any substitution or option difference and route it for review. A higher nominal channel count is not automatically an acceptable substitution if other required functions, interfaces or software differ. The complete configuration must remain suitable for the approved application and planned record workflow.
Evaluate data and workstation consequences separately
Additional acquisition capability may change the objects the organization plans to retain or the review environment it needs. Ask the supplier to demonstrate a representative saved package and explain the supported analysis workflow. Do not estimate storage, transfer time or workstation requirements from the channel label alone. The actual data volume and processing needs depend on the defined configuration and retained evidence.
Use a sample that represents the approved business need rather than the smallest convenient demonstration file. Record its size, relevant configuration and the task performed by the reviewer. The result should support a practical ownership decision about software, storage and support. It should not be extrapolated into a universal performance promise for every acquisition mode or inspection assignment.
Include the customer's required output in the comparison. A more capable instrument does not necessarily reduce the work needed to produce an agreed report or compatible data package. Ask which software functions and entitlements are included. If the customer expects independent review, test that specific task before describing the package as complete. Channel capacity and data portability answer different purchasing questions.
Keep training and approval tied to the selected capability
A larger or upgraded configuration may add functions that the team has not previously used. The employer's technical process should determine what additional instruction, qualification or authorization is needed for the intended work. Vendor product familiarization can support that process but does not automatically approve a new technique or application. Purchasing should identify the included training scope and any remaining organizational responsibility.
Do not assume that a saved setup from another instrument can be used unchanged merely because the new unit has a higher capacity. The appropriate technical review should confirm compatibility and suitability under the applicable process. The buyer can ensure that the supplier provides relevant documentation and a supported migration path, while the technical authority decides whether the resulting configuration is acceptable.
Record capability changes in the equipment history. The software and firmware change guide provides an administrative structure for the evidence and approval references. Keep the previous configuration identifiable so earlier inspection records can be understood. Updating the current register entry should not erase the fact that the instrument had a different capability when older work was performed.
Consider three hypothetical purchasing outcomes
A fictional provider has an approved application that its technical authority confirms is supported by the lower-capacity quotation. The higher-capacity alternative includes functions the company does not currently need. The buyer may select the lower-capacity package after comparing support, data workflow and complete cost. The decision is specific to that approved application and does not imply that the lower configuration suits every examination.
A second fictional provider has a defined future contract whose technical requirements exceed the existing configuration. Its review identifies the required capability and confirms the proposed package through supplier evidence and technical acceptance. The additional cost now has a concrete purpose. The company records the configuration, supporting evidence and remaining readiness tasks instead of saying simply that more channels provide better inspection.
A third fictional buyer sees a used instrument advertised only by its family name and the larger of two channel numbers. The buyer requests the full configuration and option record before treating the offer as comparable with a new quotation. If the seller cannot establish the required capability, the uncertainty remains part of the decision. A low price does not resolve a missing technical identity.
Finish with a configuration statement that staff can use
The final purchase record should identify the exact instrument configuration, the manufacturer's meaning of its notation, the approved application and the evidence supporting suitability. Include required probes, interfaces, software and retained-data functions by reference to the accepted package schedule. This gives equipment coordinators a practical way to recognize the intended unit and route a proposed substitution or upgrade for review.
In NDT Connect, use the model and notes fields to retain a concise configuration reference alongside the serial number, status and due date. The tracker does not interpret PAUT channel counts, validate scan plans or approve an equipment substitution. Keep the detailed capability worksheet and technical acceptance evidence in the organization's controlled records, where the responsible reviewer can maintain them.
The useful purchasing question is not which quotation contains the largest number. It is whether the specified hardware and software support the organization's defined examination and review requirements, with evidence that can be traced to the delivered unit. Reading the notation correctly prevents an early misunderstanding; evaluating the complete configuration turns that understanding into a defensible equipment decision.
Frequently Asked Questions
Does 16:64 mean sixty-four elements are active together?
Under the common notation explained by Evident, the first number describes simultaneous active capability and the second describes connected element capacity. Confirm the exact manufacturer’s definition for the proposed instrument.
Does a larger channel count guarantee better inspection?
No. Suitability depends on the approved application and complete instrument, probe, software and procedure arrangement.
Can PAUT channel notation be assumed to describe raw FMC retention?
No. Confirm acquisition-mode and retained-data capabilities separately for the exact configuration and enabled options.
References & Standards Cited
- Evident: Phased Array Technology, acquisition instrument notation View source ↗
- Eddyfi: Mantis instrument configuration and capabilities View source ↗
- Evident: configuration-specific computer-controlled acquisition and FMC access View source ↗
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