The Fluke 2635A Hydra Series II Data Bucket is a 21-channel data logging instrument that measures and records the following electrical and physical parameters: dc volts, ac volts, resistance, frequency, and temperature. Temperature measurements are via thermocouples or resistance-temperature detectors (RTDs). Other parameters can be measured with an appropriate transducer, such as air pressure/vacuum (using a Fluke PV350 transducer module) or DC current (using a Fluke 2600A-101 shunt resistor). When the instrument scans channels configured for measurement, readings can be displayed, printed out, and recorded. Virtually any analog input may be applied without external signal conditioning. The inputs for channels 1 through 20 are via a Universal Input Module, which plugs into the rear of the unit for a quick connect/disconnect capability. Channel 0 measurements are via the front panel input jacks using test leads (supplied). For a quick introduction to the operation of the instrument, complete the Ten- Minute Tour at the front of this manual. A summary of the Hydra Series II Data Bucket features is provided in Table 1-1 and complete specifications in Appendix A. Figure 1-1 shows the instrument front and rear panels. Operating Modes The Data Bucket may be used in a wide variety of applications using one or more of five operating modes: · Front Panel Operation · Memory Card Operation · Computer Operation · Printer Operation · Modem Operation · Channel Scanning Can be continuous scanning, scanning at an interval time, single scans, or triggered (internal or external) scans. Channel Monitoring may be used while scanning. · Channel Monitoring Make measurements on a single channel and view these measurements on the display. · Memory Card Store measurement data and meter configuration setup data on a removable nonvolatile RAM card. · Multi-Function Display Primary display shows measurement readings; also used when setting numeric parameters. Secondary display used for numeric entries, channel number selection and display, status information, and operator prompts. Annunciator display used to show measurement units, alarms review parameters, remote status, and configuration information. · Front-Panel Operation Almost all operations can be readily controlled with the front panel keys. · Measurement Input Function and Range Volts dc (VDC), volts ac (VAC), frequency (HZ), and resistance (Ω) inputs can be specified in a fixed measurement range. Autoranging, which allows the instruments to use the measurement range providing the optimum resolution, can also be selected. · Temperature Measurement Thermocouple types J, K, E, T, N, R, S and B, and Hoskins Engineering Co. type C are supported. Also, DIN/IEC 751 Platinum RTDs are supported. · Totalize Events on the Totalizing Input · Alarm Limits and Digital Output Alarm Indication · Four-Terminal Resistance Measurements (Channels 1 through 10 only) · RS-232 Computer Interface Operation · Measurement Rate Selection · Nonvolatile Memory Storage of minimum, maximum, and most recent measurements for all scanned channels. Storage of Computer Interface setup, channel configurations, and calibration values. Internal storage of measurement data: storage for 100 scans of up to 21 channels, accessible only through the computer interface.