An apparatus (20) for monitoring flotation performance apparatus comprises an arm (21) having a paddle (22) attached at one end. The apparatus (20) forms a sensor to monitor real-time flotation performance by measuring the drag exerted by the overflowing froth onto a cantilever beam arm. The strain exerted on the beam or arm can be directly correlated to the efficiency of the froth flotation process. Methods for monitoring and controlling a froth flotation process and a method to determine ash content in coal undergoing flotation are also described

A kingpin assembly includes a housing having a recess located therein, a kingpin having at least a portion located within the recess of the housing, wherein the kingpin is secured within the recess of the housing, and wherein the kingpin includes an axis extending along a length of the kingpin, and a sensor arrangement configured to sense a force exerted on the kingpin in a first direction that is substantially perpendicular to the longitudinal axis, and a second direction that is substantially perpendicular to the first direction.

A kingpin assembly includes a housing having a recess located therein, a kingpin having at least a portion located within the recess of the housing, wherein the kingpin is secured within the recess of the housing, and wherein the kingpin includes an axis extending along a length of the kingpin, and a sensor arrangement configured to sense a force exerted on the kingpin in a first direction that is substantially perpendicular to the longitudinal axis, and a second direction that is substantially perpendicular to the first direction.

A strain gauge includes a flexible substrate and a functional layer formed of a metal, an alloy, or a metal compound, the functional layer being directly on one surface of the substrate. The strain gauge includes a resistor formed of a film that includes Cr, CrN, and Cr.sub.2N and that is formed with α-Cr as a main component. The functional layer includes a function of promoting crystal growth of α-Cr and forming an α-Cr based film.

A strain gauge includes a flexible substrate and a functional layer formed of a metal, an alloy, or a metal compound, the functional layer being directly on one surface of the substrate. The strain gauge includes a resistor formed of a film that includes Cr, CrN, and Cr.sub.2N and that is formed with α-Cr as a main component. The functional layer includes a function of promoting crystal growth of α-Cr and forming an α-Cr based film.

A measurement system configured to examine a sample. The system comprises an internally reflective element, a contact member, an actuator, an optical assembly, a sensor, and a controller. The contact member and the reflective element are configured to apply a force to the sample. The optical assembly is configured to scan the sample. Whereby prior to the scan, an initial force is applied to the sample, and after the scan, a resulting force is applied to the sample. The sensor is configured to detect the resulting force applied to the sample, and the controller is configured to receive a signal from the sensor indicative of the detected resulting force. The controller is further configured to control the actuator to adjust the force applied to the sample by the contact member and the internally reflective element from the resulting force to the initial force.

A measurement system configured to examine a sample. The system comprises an internally reflective element, a contact member, an actuator, an optical assembly, a sensor, and a controller. The contact member and the reflective element are configured to apply a force to the sample. The optical assembly is configured to scan the sample. Whereby prior to the scan, an initial force is applied to the sample, and after the scan, a resulting force is applied to the sample. The sensor is configured to detect the resulting force applied to the sample, and the controller is configured to receive a signal from the sensor indicative of the detected resulting force. The controller is further configured to control the actuator to adjust the force applied to the sample by the contact member and the internally reflective element from the resulting force to the initial force.

An optical measurement system measurement system for examining a sample. The measurement system comprises an internally reflective element, a stage, an optical assembly, a chassis, and a sensor. The internally reflective element has a contact surface. The stage is positioned below the internally reflective element. The stage and the internally reflective element are configured to apply a force to the sample. The optical assembly comprises a light source and a light detector. The optical assembly is configured to scan the sample by directing source light from the light source towards the contact surface and detecting source light optically interacting with the contact surface by the light detector. The chassis is configured to support the optical assembly and the internally reflective element. The sensor is mounted to the chassis and configured to detect the force applied to the sample by the internally reflective element and the stage.

An optical measurement system measurement system for examining a sample. The measurement system comprises an internally reflective element, a stage, an optical assembly, a chassis, and a sensor. The internally reflective element has a contact surface. The stage is positioned below the internally reflective element. The stage and the internally reflective element are configured to apply a force to the sample. The optical assembly comprises a light source and a light detector. The optical assembly is configured to scan the sample by directing source light from the light source towards the contact surface and detecting source light optically interacting with the contact surface by the light detector. The chassis is configured to support the optical assembly and the internally reflective element. The sensor is mounted to the chassis and configured to detect the force applied to the sample by the internally reflective element and the stage.

A system for measuring a load lifted by a lifting machine includes a winch with a rope wound onto a drum, the drum being rotatable to wind and unwind the rope affixed to the load to lift and lower the load, end supports affixing the drum to the lifting machine, and at least one strain gauge affixed to the end supports and measuring a strain applied to the end supports by the load on the rope.