With a legacy spanning more than 50 years, Penny + Giles is a recognised leader in the design and manufacture of joystick controllers, sensors and industrial solenoids. It has extensive experience in providing solutions for monitoring and control under extreme operating conditions.
Contactless Rotary Position Sensors
The company’s extensive range of rotary position sensors offer angle measurements from 10° to 360° and use Hall effect, inductive or potentiometric technologies, all packaged in compact or rugged housings, with environmental protections to IP68 and IP69K. Its dual-output, contactless range has been specially developed to meet the operating requirements of many industrial position sensing applications in the general engineering, automation and process control sectors.
Designed with 21st century applications in mind, Penny + Giles contactless rotary position sensors use the latest advances in 12bit Hall effect sensing technology and are factory-programmed to provide OEM’s with a variety of previously unavailable options. These include single- or dual-redundant outputs, clockwise or anticlockwise rotation and measurement angles from 0-20° to 0-360° in 1° increments.
Most models can withstand operating temperatures between -40°C and +140°C (+170°C for 72 hours for NRH/TPS models); are tested to resist severe shock and vibration; and have an EMC immunity of 100V/m.
The sensors are designed to operate from a 5Vdc regulated or 9 - 30Vdc supply; and outputs can be PWM or analog voltage (nominal 0.5 - 4.5Vdc) over the measurement range, with clockwise or anticlockwise shaft rotation. A choice of 341 different electrical angles from 20° to 360° are possible and 12bit resolution (0.025%) is available over the selected measuring range with a non-linearity better than ±0.4% and temperature stability better than ±50ppm/°C. The sensor’s analog output option has a very low output noise level of less than 1mV rms.
Contactless Tilt Sensors
The company’s STT tilt sensor range uses solid-state 3D-MEMS technology to measure the sensor's inclination relative to earth's gravity. By using solid-state system-on-chip technology, the STT series provides distinct advantages in reliability, stability and compactness over fluid-based, electrolytic and pendulum operated sensors. For maximum flexibility this new range has a low power requirement of less than 6.5mA, so it can be used in hard-wired or battery-powered wireless systems.
The IP68-rated STT280 is supplied in a compact 28mm diameter corrosion-resistant body with crush proof inserts in the mounting flange. The larger STT500 is supplied in a rugged, marine grade cast aluminium housing with a protection rating of IP69K.
Both sensors can withstand operating temperatures from -40°C to +125°C and have been tested to withstand a 3m drop onto concrete (maximum 20,000g). They are available with a choice of measurement ranges from ±10°, ±20°, ±30° and ±60° and can operate from a 5Vdc regulated or 8 – 30Vdc unregulated power supply.
Contactless Linear Position Sensors
Penny + Giles’ comprehensive range of linear position sensors use non-contacting technologies and cover measurement ranges from 10 to 5000mm. A choice of models and mounting configurations, including embedded in-cylinder linear transducers, suit a wide range of hostile industrial applications.
The company’s SLT190 is designed to provide reliable, fit-and-forget position sensing (up to 500mm) within a compact transducer size for the most arduous operating environments. It can withstand operating temperatures from -40 to +150°C, has been tested to withstand shocks to 10,000g and, with EMC Immunity of 100V/m, the SLT190 is suitable for the harshest of applications.
To minimise size and the impact on the overall system, separate signal conditioning electronics (EICT or EICTM) are housed in rugged IP66 or IP68 rated enclosures. The electronics module can be located up to 10m from the transducer, away from any hostile conditions (vibration, mechanical impact, temperature) that the position transducer may encounter during operation. The result is a more reliable transducer solution, easily installed and adjusted and more flexible in the choice of outputs - including voltage, current and digital PWM.
The Penny + Giles SLH100 has been specifically designed to provide precision, cost-effective position sensing using the contactless Hall effect principle, with the sensing system comprises only two parts: the sensor and the magnetic activator. As a fully encapsulated electronic device it is intended to compete with sealed potentiometers and inductive sensors.
This robust, maintenance-free and easy-to-fit sensor can be used for a variety of control applications and its durable design and absence of mechanical linkages makes this sensor attractive for use in harsh environments - where particles, moisture, temperature and vibration can be present.
Sensors In Action
For a recent application, Penny + Giles is supplying its STT280 tilt sensors and SRH280DP rotary Hall effect sensors to Sarclad Ltd to provide critical measurements for an In-Chain Strand Condition Monitor – a precision, online measurement system used to monitor continuous casting machine rolls used in the steel making process.
The In-Chain Strand Condition Monitor (In-Chain SCM) is permanently installed in the steelmaking process to enable automatic fixed-roll alignment and roll-gap measurements to be performed at the beginning of every casting, without affecting production activities. The Penny + Giles sensors were specified to meet the stringent requirements of a system that is robustly engineered to endure the extremely hostile casting environment.
Commenting for Sarclad, In-Chain SCM manager Richard Cowlishaw says: “With a continuous cast system able to produce in excess of $1million worth of steel a day time is of the essence, so interrupting production to measure the condition of the casting machine could cost steelmakers huge amounts of money. Installing a Sarclad In-Chain SCM system ensures that measurements are taken automatically at the start of every cast, so that costly downtime is avoided and quality of product is maintained.”
The Penny + Giles STT280 tilt sensors are fitted to the In-Chain SCM to measure the fixed-roll alignment of the casting machine using spring-loaded blades that tangent pairs of rolls to measure the angles between them. The data is then processed to identify rolls and segments that are out of position relative to other rolls within each segment.
Sarclad had previously used inclinometers, but specified the Penny + Giles tilt sensor because its compact size and extremely robust construction proved more effective and robust for the application. In addition, because measurements are taken while the continuous cast system is moving, inclinometers were prone to resonate or create a spike output. In contrast, the STT280 tilt sensor features 3D-MEMS technology, which provides a naturally-damped response that is unaffected by knocking or vibration. This feature is especially important for continuous steelmaking operations where accurate measurements are vital, as Richard Cowlishaw explains.
“The steel making process involves pouring molten steel into a caster mould and oscillating the mould to prevent the liquid steel sticking to the sides while it solidifies. The vibrations from the action of the oscillator affects the measurements taken with traditional inclinometers, by producing spiked rather than smooth outputs, which corrupts the measured data.
The caster operates from ninety degrees vertical to zero degrees horizontal, so in order to accurately measure between the two angles it is necessary to measure beyond them. Penny + Giles were able to customise the STT280 sensor to measure between 92 degrees and -2 degrees, providing the calibration points we needed outside the measuring range.”
He goes onto say that Sarclad was so impressed with the Penny + Giles sensors that they have also been installed on its traditional Strand Condition Monitor, which is the offline equivalent of the online In-Chain system.
Sarclad also uses Penny + Giles SRH280DP rotary Hall effect sensors to measure gap displacement on the In-Chain SCM system, replacing the rotary inductive position sensor (RIPS) used in the original design.
Says Richard: “The RIPS were too big, were influenced by forces exerted on the shaft and used a technology that proved to be unsuitable for the application. Axial loads on the RIPS shaft also caused the output to fluctuate even though it wasn’t being rotated.” He adds that potentiometers also proved problematic because the application only needed a small length of track, which meant that the conductive grease degraded prematurely, causing spikes in the signal.
When Penny + Giles introduced the SRH280 rotary Hall effect sensor to provide uniform feedback, Sarclad immediately realised its benefits even though it was only initially launched as a single channel sensor. However, the range was programmable, which allowed the company to get the maximum resolution from the 30 degrees rotation output they required. Sarclad now fits the recently developed Penny + Giles SRH280DP two channel version, which can be configured with both channel outputs increasing with clockwise or anti-clockwise shaft rotation, or one clockwise with one anti-clockwise.
“Being a non-contact Hall effect sensor, any pressure applied to the shaft in an axial direction does not affect the output.” says Richard. “It is also available as a regulated or unregulated version, is very stable and not affected by heat or shock, which is a real bonus for this particular application.”
The SRH280DP is fitted as part of a gap transducer, which has a spring-loaded rotary arm that extends out to contact the caster rolls to provide an absolute measurement for the distance between the pair of opposing rolls.
New levels of sophistication
The latest developments in sensing and control system technology are bringing a whole new level of sophistication to monitoring and control, resulting in much more efficient operation. Highly reliable signals from the latest sensor developments, combined with intuitive control system software, mean that process control equipment can be tuned to optimise performance to individual applications. At the touch of a few buttons, routine operations can be performed throughout the process to deliver considerably better productivity.
Involving component suppliers such as Penny + Giles at the earliest possible stages of development often produces the most cost-effective solution in the shortest possible development time. This is achieved by combining Penny + Giles’ vast experience of the type and layout of equipment controls with the more subjective input of OEM engineering and marketing departments.
