Campbell Scientific's measurement and control systems are portable, versatile, rugged, and accurate, making them a valuable tool in building research studies.
Our systems feature many capabilities that surpass those of standard systems and offer more flexibility for matching systems to exact needs. For example, a single data logger could monitor temperature, relative humidity, solar radiation, wind speed, wind direction, power consumption, water consumption, vibration, load, and pressures, all at multiple locations. This allows the researcher to obtain an accurate picture of the interactions and dynamics within the tested structure.
The control capabilities of the data loggers allow temperatures and other parameters to be maintained at different levels in different parts of the facility at different times. HVAC functions can be reduced when buildings are unoccupied. Exchange between outside and inside air can occur when conditions require or are favorable, conserving energy. Systems can notify personnel by voice-synthesized telephone of conditions or problems, record data, sound alarms, and initiate shutdowns.
Our control units are programmable and provide advanced measurement and control. They perform the functions of a PLC and more.
The reliability of our control units ensures collection of time-stamped data, even under adverse circumstances. Because they have their own power supply (alkaline or rechargeable batteries), the control units continue to measure and record existing conditions during power outages. Up to 2 million data points can be stored onboard, depending on the model. Time-stamped data provides valuable information for identifying and verifying past events. In monitoring operations where temperatures or other parameters must be kept within specific ranges (to ensure the quality of products or equipment), historical data can provide important information. Harsh environments don't affect the reliability of our systems.
Statistical and mathematical functions are built into our units, allowing data reduction at the measurement site. Measurements can be processed and stored in the desired units of measure (i.e., ?F, ?C, psi, inches of water, inches of mercury, etc.).
Each control unit has multiple channel types, allowing nearly all sensor types to be measured by a single unit. For example, one control unit can measure voltage, air velocities, air temperature, relative humidity, energy use, water temperature, and steam pressure, as well as solar radiation, external temperature, wind speed, and air quality. Channel types include analog (single-ended and differential), pulse, digital I/O, and switched excitation. Most sensors connect directly to the control units, eliminating external signal conditioning. Multiplexers and other peripherals can be used to increase the number of channels and channel types.
Because our control units are programmable (without ladder logic), they can perform responsive measurement and control sequences. Powerful on-board instruction sets allow unattended measurement and control decisions based on time or conditional events. For example, alarms can be triggered, phone numbers dialed, or equipment shut down if a boiler's water temperature is outside the desired range. Our systems can even perform control based on multiple conditions or events, such as deciding to increase or decrease air exchange based on time of day, outside temperature, and/or inside temperature.
Almost any sensor may be used with the system, allowing customization for each operation. Each of our control units features a variety of channel types for flexibility in measuring many different types of sensors.
Communications options for reporting site conditions include:
The system can be monitored and controlled by an on-site or remote computer. You can even post your data on the Internet.
In a typical HVAC application, sensors monitor relative humidity, flow rates, indoor temperature, outdoor temperature, differential pressures, and equipment status. In smaller operations, only one control unit is needed. When a large number of sensors are used or when there are many monitoring locations, additional control units are used. Based on the measurements and the desired outcome, the control units actuate proportioning valves, boilers, heat exchange units, pumps, blowers, air handlers and other devices required to bring building(s) to the desired state. In case of equipment failure (or other measured event), the system sounds alarms or calls out on a phone, radio, cellphone, or other device. Data can be stored and/or transmitted to an on-site or central computer.