©Trefoil Controls Ltd. 2019


Willie McMahon – Managing Director and Co-Founder

Willie has been working in Instrumentation and Calibration since 1994 in various companies, industries and supporting different roles during that time. In response to growing business opportunities he established Trefoil Controls Ltd along with wife Claire. He brings an in-depth knowledge of instrumentation to the table and assists clients with challenging process measurement and control applications.

Willie and the team at Trefoil Controls Ltd have created specific calibration management solutions for clients in many sectors, from supporting and advising start-ups on the requirements of a calibration management system to transitioning established organisations from obsolete or outgrown software systems to web based, multi user functionality solutions.

Claire McMahon – Operations Director and Co-Founder

Having set up Trefoil Controls Ltd in 2015 along with husband Willie, Claire is the Operations Director of the company assisting with the financial and business development. Trained in Business Management and with 20 years experience working in supervisory and administration roles in the charity and private sector, Claire believes that the personal connection with customers and team members is vital in sustaining any growing business.

Paul Heffernan – Snr Instrument Engineer

Paul has an Honours Bachelor’s degree in Mechatronic Engineering and has been with Trefoil Controls Ltd since 2017 as an instrumentation engineer. He has been working as a Calibration Technician in previous positions over the course of 3 years, when not in College. At Trefoil Controls Ltd he also deals with instrument sales and calibration.

Roisin Stafford - Receptionist/Administrator

Roisin commenced working at Trefoil Controls Ltd in 2018 and brings a great deal of knowledge and experience to her role gained from previous positions in the service and industrial sectors. She is the first point of contact for enquiries and is always on hand to support both customers and the engineering team.

Stephen Nulty – Apprentice Engineer

Stephen has been an apprentice instrumentation engineer at Trefoil Controls Ltd since 2017 where he is gaining experience in the field in between attending college to gain a more robust technical knowledge of the trade. 

Roisin Price – Administrator

Roisin works part time with Trefoil Controls Ltd assisting the admin team in between attending college to study Early Childhood Education.  She has been assisting the company since its foundation using her organisational and admin skills to help grow the business to where it is today.