Method of calibrating a daylight sensor

A method of calibrating a daylight sensor for measuring a light intensity in a space, the daylight sensor operating as part of a lighting control system that comprises a dimmer switch for controlling a present light intensity of a lighting load, so as to control a total light intensity on a task surface in the space, the method comprising the steps of:

• installing the daylight sensor on a surface;
• adjusting the present light intensity of the lighting load, such that the total light intensity on the task surface is at a target task surface light intensity;
• actuating a button on the daylight sensor;
• measuring the total light intensity at the daylight sensor in response to the actuation of the button on the daylight sensor;
• the daylight sensor subsequently transmitting the total measured light intensity to the dimmer switch;
• the dimmer switch turning the lighting load on to a maximum light intensity;
• subsequently measuring the light intensity at the daylight sensor to determine a total measured light intensity;
• the daylight sensor subsequently transmitting the total measured light intensity to the dimmer switch;
• the dimmer switch subsequently turning the lighting load off;
• subsequently measuring the light intensity at the daylight sensor to determine a measured light intensity from only daylight;
• the daylight sensor subsequently transmitting the measured light intensity from only daylight to the dimmer switch;
• and
• the dimmer switch calculating a daylight gain in response to the total light intensity measured by the daylight sensor and the present light intensity of the lighting load and an electric light gain in response to the total measured light intensity and the measured light intensity from only daylight.

A method of calibrating a daylight sensor for measuring a light intensity in a space, the daylight sensor operating as part of a lighting control system that comprises a dimmer switch for controlling a present light intensity of a lighting load, so as to control a total light intensity on a task surface in the space, the method comprising the steps of:

• installing the daylight sensor on a surface;
• adjusting the present light intensity of the lighting load, such that the total light intensity on the task surface is at a target task surface light intensity;
• actuating a button on the daylight sensor;
• measuring the total light intensity at the daylight sensor in response to the actuation of the button on the daylight sensor;
• the daylight sensor subsequently transmitting the total measured light intensity to the dimmer switch;
• placing a second daylight sensor on the task surface;
• measuring the total light intensity at the second daylight sensor in response to the actuation of the button on the daylight sensor;
• the second daylight sensor subsequently transmitting the total measured light intensity to the dimmer switch;
• and
• the dimmer switch subsequently calculating a daylight gain in response to the total light intensities measured by both daylight sensors and the present light intensity of the lighting load.

A method of calibrating a daylight sensor for measuring a light intensity in a space, the daylight sensor operating as part of a lighting control system that comprises a load control device having a dimmer circuit for controlling the power delivered to a lighting load, the method comprising the steps of:

• installing the daylight sensor on a surface;
• the daylight sensor periodically measuring the light intensity in the space;
• comparing the measured light intensity to a threshold;
• the dimmer circuit adjusting the intensity of the lighting load to two predetermined intensities when the measured light intensity has dropped below the threshold;
• the daylight sensor measuring the magnitude of the light intensity in the space when intensity of the lighting load is at each of the predetermined intensities to generate two electric-light-only measured light intensity values, each of the electric-light-only measured light intensity values representative of the light intensity of only the lighting load;
• and
• storing the two measured light intensities from below the threshold in a memory.

A method of calibrating a daylight sensor for measuring a light intensity in a space, the daylight sensor operating as part of a lighting control system that comprises a load control device for controlling the power delivered to a lighting load, the method comprising the steps of:

• connecting the daylight sensor to a power source;
• installing the daylight sensor on a surface;
• the daylight sensor starting a timeout timer when the daylight sensor is connected to the power source;
• the daylight sensor periodically measuring the light intensity in the space;
• the daylight sensor storing each of the periodic measured light intensities and a respective time of day in a memory;
• determining the time of day of a lowest one of the measured light intensities in the memory if the timeout timer expires before the measured light intensity has drops below the threshold;
• comparing the measured light intensity to a threshold;
• the load control device adjusting the intensity of the lighting load to a predetermined intensity when the measured light intensity has dropped below the threshold;
• the daylight sensor measuring the magnitude of the light intensity in the space when intensity of the lighting load is at the predetermined intensity to generate an electric-light-only measured light intensity value, the electric-light-only measured light intensity value being representative of the light intensity of only the lighting load;
• and
• storing the electric-light-only measured light intensity value.

A method of calibrating a daylight sensor for measuring a light intensity in a space, the daylight sensor operating as part of a lighting control system that comprises a load control device for controlling the power delivered to a lighting load, the method comprising the steps of:

• installing the daylight sensor on a surface;
• the daylight sensor periodically measuring the light intensity in the space;
• comparing the measured light intensity to a threshold;
• the load control device adjusting the intensity of the lighting load to a predetermined intensity when the measured light intensity has dropped below the threshold;
• the daylight sensor measuring the magnitude of the light intensity in the space when intensity of the lighting load is at the predetermined intensity to generate an electric-light-only measured light intensity value, the electric-light-only measured light intensity value being representative of the light intensity of only the lighting load;
• and
• storing the electric-light-only measured light intensity value in a memory;
• the daylight sensor subsequently starting a recalibration timer;
• the load control device re-adjusting the intensity of the lighting load to the predetermined intensity when the recalibration timer expires;
• the daylight sensor re-measuring the magnitude of the light intensity in the space after the recalibration timer expires;
• and
• storing the re-measured light intensity in the memory.

A daylight sensor for measuring a light intensity in a space, the daylight sensor adapted to operate as part of a lighting control system that comprises a dimmer circuit for controlling the amount of power delivered to a lighting load, the daylight sensor comprising:

• a photosensitive circuit operable to generate a light intensity control signal in response to the light intensity in the space;
• a transmitter for transmitting signals;
• a controller coupled to the photosensitive circuit and the transmitter, the controller operable to transmit signals in response to the light intensity control signal, the controller further operable to periodically measure the light intensity in the space, compare the measured light intensity to a threshold, and transmit a command to adjust the intensity of the lighting load to a predetermined intensity when the measured light intensity has dropped below the threshold;
• a battery for powering the photosensitive circuit, the transmitter, and the controller;
• and
• a memory coupled to the controller for storing measured light intensities;
• wherein the controller measures the magnitude of the light intensity in the space when the light intensity of the lighting load is at the predetermined intensity to generate a electric-light-only measured light intensity value, and stores the electric-light-only measured light intensity value in the memory, the electric-light-only measured light intensity value being representative of the light intensity of only the lighting load, the controller starting a timeout timer when the controller becomes powered by the battery, the controller operable to store each of the periodic measured light intensities and a respective time of day in the memory, the controller further operable to determine the time of day of a lowest one of the measured light intensities in the memory if the timeout timer expires before the measured light intensity has dropped below the threshold.

A daylight sensor for measuring a light intensity in a space, the daylight sensor adapted to operate as part of a lighting control system that comprises a dimmer circuit for controlling the amount of power delivered to a lighting load, the daylight sensor comprising:

• a photosensitive circuit operable to generate a light intensity control signal in response to the light intensity in the space;
• a transmitter for transmitting signals;
• a controller coupled to the photosensitive circuit and the transmitter, the controller operable to transmit signals in response to the light intensity control signal, the controller further operable to periodically measure the light intensity in the space, compare the measured light intensity to a threshold, and transmit a command to adjust the intensity of the lighting load to a predetermined intensity when the measured light intensity has dropped below the threshold;
• and
• a memory coupled to the controller for storing measured light intensities;
• wherein the controller measures the magnitude of the light intensity in the space when the light intensity of the lighting load is at the predetermined intensity to generate a electric-light-only measured light intensity value, and stores the electric-light-only measured light intensity value in the memory, the electric-light-only measured light intensity value being representative of the light intensity of only the lighting load, the controller starting a recalibration timer after the photosensitive circuit measures the magnitude of the light intensity in the space when intensity of the lighting load is at the predetermined intensity, transmits a command to adjust the intensity of the lighting load to the predetermined intensity when the recalibration timer expires, re-measures the magnitude of the light intensity in the space after the recalibration timer expires to generate a re-measured electric-light-only light intensity value, and stores the re-measured electric-light-only light intensity in the memory.

A method of calibrating a daylight sensor for measuring a light intensity in a space, the daylight sensor operating as part of a lighting control system that comprises a dimmer switch for controlling a present light intensity of a lighting load, so as to control a total light intensity on a task surface in the space, the method comprising the steps of:

• placing the daylight sensor on the task surface;
• actuating a button on the daylight sensor to adjust the present light intensity of the lighting load, such that the total light intensity on the task surface is at a target task surface light intensity;
• measuring the light intensity at the daylight sensor to generate a total-at-task-surface light intensity value;
• turning off the lighting load;
• measuring the light intensity at the daylight sensor to generate a daylight-at-task-surface light intensity value;
• installing the daylight sensor on a ceiling surface;
• adjusting the present light intensity of the lighting load, such that the total light intensity on the task surface is at the target task surface light intensity;
• measuring the light intensity at the daylight sensor to generate a total-at-ceiling light intensity value;
• turning off the lighting load;
• measuring the light intensity at the daylight sensor to generate a daylight-at-ceiling light intensity value;
• and
• calculating one or more gains using the total-at-task-surface light intensity value, the daylight-at-task-surface light intensity value, the total-at-ceiling light intensity value, and the daylight-at-ceiling light intensity value.

A method of calibrating a first daylight sensor for measuring a light intensity in a space, the first daylight sensor operating as part of a lighting control system that comprises a dimmer switch for controlling a present light intensity of a lighting load, so as to control a total light intensity on a task surface in the space, the method comprising the steps of:

• installing the first daylight sensor on a ceiling surface;
• placing a second daylight sensor on the task surface;
• measuring the light intensity at the first daylight sensor to generate a total-at-ceiling light intensity value;
• adjusting the present light intensity of the lighting load, such that the total light intensity on the task surface is at a target task surface light intensity;
• measuring the light intensity at the second daylight sensor to generate a total-at-task-surface light intensity value;
• turning off the lighting load;
• measuring the light intensity at the first daylight sensor to generate a daylight-at-ceiling light intensity value;
• measuring the light intensity at the second daylight sensor to generate a daylight-at-task-surface light intensity value;
• and
• calculating one or more gains using the total-at-task-surface light intensity value, the daylight-at-task-surface light intensity value, the total-at-ceiling light intensity value, and the daylight-at-ceiling light intensity value.

A method of calibrating a daylight sensor for measuring a light intensity in a space, the daylight sensor operating as part of a lighting control system that comprises a dimmer switch for controlling a present light intensity of a lighting load, so as to control a total light intensity on a task surface in the space, the method comprising the steps of:

• placing the daylight sensor on the task surface;
• measuring the light intensity at the daylight sensor;
• displaying a representation of the total light intensity measured by the daylight sensor on a visual display of the daylight sensor;
• adjusting the present light intensity of the lighting load until the visual display on the daylight sensor displays a representation of a target task surface light intensity, such that the total light intensity on the task surface is equal to the target task surface light intensity;
• storing the present light intensity of the lighting load in a memory;
• measuring the light intensity at the daylight sensor to generate a total-at-task-surface light intensity value;
• turning off the lighting load;
• measuring the light intensity at the daylight sensor to generate a daylight-at-task-surface light intensity value;
• installing the daylight sensor on a ceiling surface;
• adjusting the present light intensity of the lighting load to the stored light intensity in the memory;
• measuring the light intensity at the daylight sensor to generate a total-at-ceiling light intensity value;
• turning off the lighting load;
• measuring the light intensity at the daylight sensor to generate a daylight-at-ceiling light intensity value;
• and
• calculating one or more gains using the total-at-task-surface light intensity value, the daylight-at-task-surface light intensity value, the total-at-ceiling light intensity value, and the daylight-at-ceiling light intensity value.

A method of calibrating a daylight sensor for measuring a light intensity in a space, the daylight sensor operating as part of a lighting control system that comprises a dimmer switch for controlling a present light intensity of a lighting load, so as to control a total light intensity on a task surface in the space, the method comprising the steps of:

• actuating a button on the daylight sensor until a visual display of the daylight sensor displays a representation of a target task surface light intensity;
• automatically adjusting the present light intensity of the lighting load, such that the total light intensity on the task surface is equal to the target task surface light intensity;
• placing the daylight sensor on the task surface;
• measuring the light intensity at the daylight sensor to generate a total-at-task-surface light intensity value;
• turning off the lighting load;
• measuring the light intensity at the daylight sensor to generate a daylight-at-task-surface light intensity value;
• installing the daylight sensor on a ceiling surface;
• adjusting the present light intensity of the lighting load, such that the total light intensity on the task surface is at the target task surface light intensity;
• measuring the light intensity at the daylight sensor to generate a total-at-ceiling light intensity value;
• turning off the lighting load;
• measuring the light intensity at the daylight sensor to generate a daylight-at-ceiling light intensity value;
• and
• calculating one or more gains using the total-at-task-surface light intensity value, the daylight-at-task-surface light intensity value, the total-at-ceiling light intensity value, and the daylight-at-ceiling light intensity value.