Procter and Chester (Measurements) Ltd
Established in 1983, PCM offer over 30 years’ experience in the design and manufacture of load cells and supply of instrumentation. Our in-house design team build bespoke customer load cells.
We also offer in-house load cell repair, load cell calibration and load cell hire service. We configure strain gauge installations to customers’ requirements, in-house/on-site, static/dynamic, -269°C/+1000°C, steel/composite, etc.
All our load cells and strain gauging services are covered by our commitment to ISO 9001:2008 approval.
Operating under ISO 9001:2008, PCM has an experienced design team that can suggest and provide load cells and instrumentation from our standard range. If a standard design does not fit your requirements, we will design a custom load cell to fulfil your application. Quantity is not an issue, whether it is a one or multiple off.
We have a unique ability to respond quickly to bespoke projects. We listen to the customer and supply drawings and specifications which require customer authorisation prior to manufacture. This ensures that you know what you are getting.
If the impossible has been requested using load cell technology, we will inform the customer so that they know the limitations and together agree a solution or a compromise on the specification.
The load cells we manufacture are strain gauge based using the Wheatstone bridge principle which converts an applied force (mechanical movement) into a linear electrical signal. Find out more about our standard load cell range here.
With over 30 years expertise in the industry, PCM can offer you an efficient, cost-effective and quality load cell design and build service. We aim to achieve the quickest service and most competitive prices without compromising on excellence.
PCM does offer an extensive range of standard load cell solutions, but when an ‘off the shelf’ solution simply isn’t suitable, we have an experienced in-house design team who are able to design a bespoke load cell, transducer or load pin to suit your exact requirements and dimensions. As a full service company, we then complete the process by manufacturing the load cell, supply instrumentation to complete your application as well as setting up and calibrating the system if required.
If you find yourself restricted by budgets or the dimensions available to work with on a project – it may even be possible that we can modify existing designs. Past projects have involved converting free issued tools or parts into working load cells that fit directly in-situ without any modification to the machinery.
All designs by PCM are undertaken as per our ISO 9001:2008 accreditation, providing assurance for our customers that when a repeat requirement occurs in future, we can refer to the original designs/calculations and performance data.
PCM have been strain gauging free issue items ranging from R&D items, motorsport components, buildings, bridges, boats, etc, since we were established in 1983. We are completely independent and use only most suitable consumables for a project. Our experience ranges from cryogenic (-269°C) to high temperature (+800°C), static to fatigue, specialist metals to glass, composite and plastics.
Each installation is supplied with an Installation Sheet for traceability. This document includes the strain gauge data, strain gauge readings and photographs. All this data is documented in our technical filing system for future projects. This information will aid future projects for continuous improvement in strain gauging and load cell manufacture. This in turn, leads to a quality product that remains reliable, economic to produce and delivered within an agreed time scale - all based on experience!
Load cells are strain gauge based transducers which are used to measure load, overload, or tension conditions. Load pins are a version of load cell that are typically installed into machines in the place of solid shafts, whereas load cells act as a direct component in an assembly. Load pins designed by PCM work on the double shear stress method.
PCM load pins are entirely custom fit. All units are designed completely around the customer requirements and if required, assistance is available to guide these decisions from our experienced Technical team.
Load pins are versatile pieces of equipment and are used in a large variety of applications, such as: cranes, hoisting gear, winches, etc. Rope, chain, and brake anchors, bearing blocks, pivots and shackles, elevators and floor conveyors as well as in applications for the agricultural, aviation, chemical and R&D industries.
As all of the load pins that PCM manufacture are made to order, we request that the load pin questionnaire (refer to Page 4 of our datasheet) is completed and sent into our Sales team. Once received, our team of engineers will review your enquiry and confirm if the load pin criteria is mechanically achievable and safe. We will then submit a quotation complete with a competitive lead time. When a purchase order has been received, a technical outline drawing and specification will be submitted to the customer for approval prior to manufacture.
All PCM load pins are supplied with calibration certificates obtained using test machines traceable to National Standards. However, we do recommend that an in-situ calibration is carried out to obtain maximum performance.
To complete your system, PCM can offer you built-in amplifiers if required, we can also supply almost any instrumentation desired, ranging from equipment such as wireless telemetry, large displays, cased panel/hand held indicators to summation devices and overload/slack rope detection equipment.
Load pins are also available supplied with a shackle, standard and custom options available see PCM shackle load pins.
PCM not only offer the load cell/strain gauging aspect of your project, we're a full service company and can supply you with the instrumentation required by your application as well as a set-up and calibration service so that when the system arrives with you in most cases, it will be a case of unpacking and connecting the equipment together and away you go.
Amplifiers are essentially electronics that do not have displays. They transform a load cell signal (millivolts per volt or mV/V) to another type of signal i.e.: analogue (for example, mA or V) or also a digital output (for example RS232 and/or RS485).
The load cell and amplifier will require setting up and calibrating together for the system to work correctly. This is done by applying a known force to the load cell and the amplifier gain to be set.
Any instrumentation will power the load cell. The mV/V signal coming back from the load cell is converted by the indicator and displays the force in a unit (for example KG, kN, Te, lb etc - whatever your preference). The indicators are either encased so that the operator can either use it on the move (if battery powered) or be a permanent fixture, for example, wall or panel mounted.
The load cell and indicator, same as the amplifier, will require calibrating together for the system to work correctly.
Above are some of the most commonly used types of instrumentation, PCM can also offer you a range of large displays and wireless communications that may be important to your project.
Wireless communication comes in three forms:
- Radio Telemetry: A transmission of data from a remote source via a radio to a receiving station for recording and analysis.
- Inductance: A contactless method of supplying power to (in this case) a strain gauge bridge. The signal is then transmitted back to the electronics.
- Slip Ring: Consists of a conductive band mounted on a shaft and is insulated from it. The Wheatstone bridge is connected to the bands (usually four off). Fixed brushes or contacts make contact on to the bands to transfer power to the bridge and signal back to the static instrumentation.
PCM offer a repair and calibration service for damaged or suspect working load cells. Similar to our calibration service, we’re able to work on the majority of load cells regardless of their manufacturer or capacity thanks to our knowledge base built up over 30 years in the industry.
Our repair service could eliminate the need to purchase new, replacement load cells and so making considerable savings. Each load cell is fully tested and investigated to diagnose the problem and a list of the faults will be presented along with our recommendations. We will always propose the most cost effective solution for you.
A repair is subject to available parts and only available if the product has not been subjected to excessive physical overload or electrical damage (to the instrumentation). The load cell is tested and load tested to ensure optimum performance before its return.
If you’d like to discuss your equipment with one of our engineers to work through the problem and troubleshoot it over the phone, or if you’d like to double check that we can help with a particular piece of equipment, please do get in touch. With some load cells/instruments, it may be easiest to send us some photos in an email along with a quick description of the fault you’re experiencing and we can respond to you with the best course of action, whether to send it in to PCM for a full investigation or some other remedial course.
If your application is a one-off test, or you are unable to justify purchasing a new load cell or system, PCM has a selection of load cells (ranging up to 500Te) and instrumentation that are available for hire.
As customer requirements vary, our load cells and instruments are not permanently paired and as such we can cater for most projects. With this in mind, a calibration traceable to National Standards is performed before every hire which ensures the results of your test are accurate, every time.
For your convenience, the system can be set up and calibrated in the units of your choice (i.e. KG, kN, Te, or lbs etc). Our standard calibration is performed over five incremental points and repeated three times to demonstrate the repeatability of the system. Calibration certificates are supplied with the hire equipment. The certificate also contains our test rig and calibration instrument reference numbers for traceability purposes.
Contact us to discuss your application with one of our engineers and we can propose a system ideally suited to your requirements.
It’s good practice when you have a load cell system or a set of load cells, to have them calibrated annually at least to ensure that they are performing to specification. At PCM, we have a very experienced team in our calibration workshop and we’re able to work on the majority of load cells regardless of their manufacturer, catering for cells ranging from small to very large capacities. All of our test machines are independently calibrated by a UKAS laboratory using verification equipment calibrated to BS EN ISO 376:2011, every 12 months.
The PCM calibration experience is bespoke to your equipment/application needs, we’re able to calibrate in tension, compression or torsion in the desired units of calibration over the number of linearity points required and also supply a shunt calibration resistor if necessary. See more on our calibration services here.
A transducer is a generic name that is a device which is usually electronic that converts a physical attribute to a measurement signal.
PCM offer three types of transducer:
- Pressure: Measures gas or liquid pressure. Pressure is an expression of the force required to stop a fluid from expanding. The transducer generates a signal from the pressure imposed upon it.
- Torque: Measures the torque (or twisting motion) on a static or rotating system. The static torque element has little movement and therefore more economic to manufacture and purchase. Rotary or dynamic torque is more complicated as the signal needs to be transferred using slip rings, wireless telemetry or rotary transformers/inductance technology so that the strain gauged shaft can continuously rotate.
- Displacement: Measures distance. The displacement transducers that PCM offer are slightly different to standard units. They have a strain gauge/Wheatstone bridge. The benefit here is that if the customer has existing electronics that uses strain gauge/load cell technology, they can use them with these sensors.