One example discloses a ratiometric device, including: a current source having a first current, a second current different from the first current, and a current-select program; a sensor device responsive to a gas and having a sensor-cold temperature T(cold,sens) in response to the first current and a sensor-hot temperature T(hot,sens) in response to the second current; a reference device having a reference-cold temperature T(cold,ref) in response to the first current and a reference-hot temperature T(hot,ref) in response to the second current; and wherein the ratiometric device includes a temperature difference ratio output based on T(cold,sens), T(hot,sens), T(cold,ref) and T(hot,ref).

A current detection module capable of differentiating and quantifying contribution to a current signal generated by a sensor in response to stimulation by a certain target source from contributions from sources other than the target source (ambient sources) is disclosed. As long as the contribution from the target source comprises a pulsed signal, the module may synchronize itself to the pulse(s) so that there is a predetermined phase relationship between the pulse(s) and functions carried out by various stages of the module. The module may be re-used to also detect and quantify contributions from ambient sources by presenting these contributions to the module as pulses that trigger synchronization of the module. To that end, a detection system disclosed herein is based on the use of such current detection module and allows mode switching where, depending on the selected mode of operation, the module is configured to perform different measurements.

A method for obtaining board parameters of a printed circuit board, including the following steps: obtaining parameter information of a stripline on the printed circuit board; obtaining physical parameters of the stripline based on the parameter information of the stripline and a predetermined electromagnetic simulation application; calculating required board parameters of the printed circuit board based on the parameter information and the physical parameters of the stripline. In the present disclosure, the physical parameters of the stripline are obtained based on the physical nature of the stripline on the printed circuit board, and there is no need for fitting or adopting a hypothetical model in order to obtain board parameters corresponding to each frequency point of the stripline; the present disclosure is simple and straightforward during operation, and the obtained board parameters of the printed circuit board are highly accurate.

A current detection module capable of differentiating and quantifying contribution to a current signal generated by a sensor in response to stimulation by a certain target source from contributions from sources other than the target source (ambient sources) is disclosed. As long as the contribution from the target source comprises a pulsed signal, the module may synchronize itself to the pulse(s) so that there is a predetermined phase relationship between the pulse(s) and functions carried out by various stages of the module. The module may be re-used to also detect and quantify contributions from ambient sources by presenting these contributions to the module as pulses that trigger synchronization of the module. To that end, a detection system disclosed herein is based on the use of such current detection module and allows mode switching where, depending on the selected mode of operation, the module is configured to perform different measurements.

A clamp meter includes a meter body and a clamp jaw assembly mounted to the meter body. The clamp jaw assembly includes a first clamp jaw and a second clamp jaw that are movable in relation to each other between a closed position and an open position. In the closed position, distal ends of the first and second clamp jaws meet to define an enclosed area between the first and second clamp jaws, and in the open position, the distal ends of the first and second clamp jaws separate from each other to define a gap allowing a wire under test to pass therethrough. The clamp meter further includes a locking slider positioned within a slot inside the meter body. A switch assembly moves the locking slider longitudinally within the slot between locked and unlocked positions. In the locked position, the locking slider blocks the first clamp jaw from movement.

A method for measuring a voltage using a capacitive voltage divider (CVD) and an analog-to-digital converter includes the steps of measuring a bandgap or reference voltage and determining a first code value of the bandgap or reference voltage, charging a first capacitor to a voltage to be measured and determining a second code value of voltage of the first capacitor, charging a second capacitor to a second known voltage and determining a third code value of voltage of the second capacitor, and determining the voltage to be measured by applying the first, second, and third code values.

A clamp meter includes a meter body and a clamp jaw assembly mounted to the meter body. The clamp jaw assembly includes a first clamp jaw and a second clamp jaw which are movable in relation to each other between a closed position and an open position. In the closed position, distal ends of the first and second clamp jaws meet to define an enclosed area between the first and second clamp jaws, and in the open position, the distal ends of the first and second clamp jaws are separate from each other to define a gap allowing a wire under test to pass therethrough. The clamp meter further includes a locking member mounted within the meter body. The locking member is operable to releasably lock the first and second clamp jaws in the closed position.

An analog signal conditioning device and method employing a multi-path feedback mechanism to actively minimize the error of the overall desired signal conditioning transfer function to produce a corrected output signal, initially and over temperature, by exploiting characteristics of resistances manufactured simultaneously on a common thermally conductive substrate.