Is this chargeable, or part of the quotation?

Application engineering of the kind described here normally accompanies a quotation — telling you which instrument to buy is part of selling you the right one. Larger pieces of work, where the scope goes beyond selecting and sizing the points, are agreed separately in advance. We will tell you which of the two your request is before we start, not after.

Will you specify an instrument you do not supply?

We will tell you honestly when the right answer is a technology or a brand we do not carry, because a point specified wrongly comes back to us anyway — as a complaint, a repair or a measurement that nobody trusts. What we cannot do is pretend to be independent: we represent manufacturers, and where our own portfolio fits we will say so plainly.

We already have a design from our contractor. Can you review it?

Yes, and it is a good use of the service. A review looks at whether each instrument suits its duty, whether the installation gives it what it needs, and whether anything has been specified into a corner. It is far less work than a specification from scratch and it catches the errors that are expensive after commissioning.

How much detail do you need from us?

The fluid and its condition, line size, flow range, pressure, temperature, the accuracy the point has to deliver and what the reading is used for. If some of that is unknown, say so — an unknown is a design input too, and pretending it is known is how the wrong instrument gets bought.

Before the purchase order

Instrument Selection & Application Engineering

Choosing the measuring principle, the size and the materials for the actual fluid, line and duty — so the measurement is right before anything is installed.

Most measurement problems are decided before the instrument arrives. A meter sized for the nameplate flow rather than the real one spends its life at the bottom of its range; a technology chosen for the fluid on the datasheet fails on the fluid actually in the line; a device specified without the straight runs it needs reads a disturbed profile forever. SEMAC has specified process instrumentation since 1994, and this is the part of the work where an hour of engineering is worth more than anything that can be done later.

What it covers

Choosing the measuring principle

Electromagnetic, Coriolis, ultrasonic, vortex, thermal, differential pressure, radar, guided wave, hydrostatic — each is excellent somewhere and wrong somewhere else. The fluid, its conductivity, solids and gas content, and what you need to know about it decide which.

Sizing for the real duty

Sizing against the actual minimum, normal and maximum flow rather than the line size, so the instrument spends its working life in the part of its range where it is accurate.

Installation assessment

Straight runs, orientation, immersion depth, impulse lines and where in the piping the point should sit. Reviewed before the order, because after installation the options narrow to expensive ones.

Materials, ratings and approvals

Wetted materials against the process chemistry, pressure and temperature ratings, hygienic requirements, hazardous-area classification and the certification the point actually needs.

Signals and integration

Output and protocol — 4–20 mA, HART, Modbus, PROFIBUS, pulse — chosen for the control system that has to receive it, plus what the DCS or PLC side needs to be told.

Specification and documentation

A written proposal you can put in front of a colleague, a contractor or a budget holder: what is proposed, why, and what alternatives were considered.

How we work

1
Tell us the point, not the product
The fluid, the line size, the flow range, the pressure and temperature, the accuracy you need and what the reading is used for. That is enough to start; a part number is not.
2
We come back with options, not one answer
Usually two or three workable approaches with their trade-offs — cost, accuracy, installation effort, what each needs from the piping — rather than a single recommendation you cannot interrogate.
3
The installation is reviewed before it is ordered
Where the point will sit, what is upstream and downstream of it, and whether the location needs changing. This is the step that is cheap now and expensive later.
4
You get it in writing
A specification and a proposal, so the reasoning survives the meeting and can be checked by whoever inherits the plant.

What you receive

A written instrument specification for each point
The measuring principle proposed, and why the alternatives were not
Sizing against your real minimum, normal and maximum duty
Installation requirements — straight runs, orientation, immersion, impulse lines
Materials, pressure and temperature ratings, and any hazardous-area certification needed
Output signal and protocol, with what the control system side must be configured for

When you need it

A new measurement point

A new line, a new tank, a new unit, or a point that was never instrumented and now needs to be.

Replacing something that never worked well

An instrument that has been fought with for years is usually the wrong instrument, not a faulty one.

The process changed

A new product, a different fluid, a change in throughput or temperature can invalidate a choice that was correct when it was made.

A project that needs a specification

Tender documents, contractor packages and budget approvals that need instrument specifications written by someone who will also have to make them work.

Specify the baseline at the same time

The cheapest moment to establish what an instrument really reads is when it is new and nothing has drifted yet. A baseline taken at handover is what every later comparison is measured against.

Verification & calibration services

Common questions

Keep your instrumentation performing at its best

Speak with SEMAC's service team to discuss your maintenance needs and plan your verification & calibration service.

Contact service team Technical services