SDR31 This unit is the least expensive Data Recorder I know of and packs a punch in terms of functionality. The SDR31 has the full functionality of the up market, SDR33 but is cheaper due to it not as shockproof or rainproof . I have seen these units mishandled and were able to cope with it quite well. This unit also has a unique feature where if you find having to use two hands is cumbersome the read key on the side of the machine is a clever concept. The menus are configurable to "hide" areas you do not use.

Weight 0.43 kg including batteries Power Single 9-volt alkaline battery is standard (NiCd cell optional) Power Backup Supercapacitor backup for battery replacement only CPU V25 16 bit with 8 MHz clock speed Operating System RAM resident DR-DOS Keyboard 46-key alphanumeric, water and dust resistant latex Display Supertwist (STN) 8-line X 20-character backlit display with graphics support ROM Memory 256K "flash" EPROM; can be reprogrammed without removal Interface Ports Top: DE9 with TTL (adaptor for limited RS232) Bottom: RJ41 with full RS232 (ten pin) Operating Temperature 0C to +40C

Software The SDR31 supports several "setting out" methods of staking out points on lines, arcs and parallel offsets. With the Taping from Baseline feature, you can pick up detail by distance and offset from a predefined baseline. The Slope Staking function is streamlined and easy. The Traverse Adjustment feature can be used with traverse data collected in either Set Collection or Topography. 3-D traverse data can be collected in any manner, including non-consecutive set-ups. The SDR31 can then do some of the thinking for you, like calculating precision and errors of closure, adjust traverse and angle or elevation adjustment. The Topography program helps increase data validity by automatically calculating and displaying the difference in observed positions. When a point is observed more than once, you may choose to replace the old observation, store the new observation under a different point number, or average the two observations for a stronger result. Differences are keyed by user-defined tolerance settings. The Control Job feature lets you mark a job which contains control point information. If ou try to recall the coordinates of a control point and the point isn't in the current job file, the control job file is accessed for optimum convenience. Roading is accomplished by loading or keying in the horizontal and vertical alignment and template information into the SDR31. When you tell it what stationing and offset or coordinate point you wish to set out, the SDR31 will give you angles and distances to set out that point in 3-D. Horizontal and vertical offsets and checking of roads under construction may also be easily accomplished with this program. *String Road Setting Out lets you load design data from a road design package (such as Sokkia ROADING Software) and set them out by name of string, station and offset. Superelevation parameters are user-defined. Left and right definitions and calculations are independent of each other. COGO features like setting out coordinates, resection and inverse are also included. The SDR31 interpolates elevations linearly and allows you to check pipe grades and alignments. Plus, it's easy to subdivide lines and arcs or calculate point projections. The Leveling program eliminates transcription and math errors; no more manual note taking. Can be used in manual mode or with Sokkia's SDL30 Digital Level. Reciprocal Vertical Calculations improves the accuracy of your elevations.