Description
The RM15-D Resistance Meter forms the heart of a versatile measuring system for rapid area or vertical profile measurements. Used with a PA20 probe array (or the earlier PA5) the RM15-D is ideally suited for use with conventional single arrays such as the Twin, Pole-Pole, Double-Dipole, Wenner, Schlumberger, Gradient etc. An expansion port allows the RM15-D to control multi-probe systems via the MPX15 multiplexer module. This allows multiplexing multi-depth Twin and other arrays that can be configured using the PA20/PA5 probe array. The RM15-D is an integral part of the MSP40 Mobile Sensor Platform, a wheeled resistance array that will provide rapid and detailed resistance surveys.
The RM15-D is available in two versions, BASIC and ADVANCED, both having built-in data loggers with memory capacities of 3600, 15000 or 30000 readings. The logger provides powerful functions for fast and efficient surveys, permitting one person surveys, and keeps track of the survey position, giving both audible and visual indication of current survey position. Readings may be logged manually, or automatically by a special current sense circuit. The modular plug-in card design allows easy upgrade from BASIC to ADVANCED meter and increase of memory capacity. An analogue output is provided for interfacing to external devices.
RM15-D Applications
- Archaeological surveys.
- Geological surveys.
- Environmental surveys.
- Civil Engineering.
- Mineral prospection.
Logger
Data Logger
Readings are stored in a non-volatile memory which may be partitioned into grid sizes of 10m, 20m or 30m square, with reading interval being either 1m or 0.5m. The data logger keeps track of survey position for both zig-zag and parallel traverses and displays current grid, line number and line position. An additional survey tracking parameter is introduced when using the MPX15. Incorrect readings may be deleted singly, or as a complete line, with one keystroke. A dummy reading can be inserted if a physical obstacle prevents a true reading being taken or a line may be completed with dummy readings, again with one keystroke. A mirror image “complete” line key is also provided for zig-zag surveys when part of the standard grid cannot be surveyed. An ENABLE LOG key controls data logger functions thus preventing accidental loss of data.
Auto-logging
Due to a special current sense circuit in both the BASIC and ADVANCED RM15-D logging can be automatic with any probe configuration that has a current probe mounted on the mobile frame, for example the Twin array. The operator simply inserts the probes of the mobile frame into the ground and the RM15 will determine when the reading has settled, log it, and then give an audible beep to tell the operator to move onto the next reading. This mode of operation greatly reduces errors and operator fatigue, leading to a considerable increase in area survey speed – typically 400 readings may be taken in about 12 minutes. Auto-logging with the MPX15 multiplexer enables large data sets to be acquired very rapidly.
Data Exmples
Example resistance survey showing walls of a medievel cemetary and buildings
Accessories
The RM15-D requires a probe array to be able to take measurements and software to download, process and display the data. Accessories presently available include:
- PA3 Probe Array
- PA20 Multi-Probe array
- MPX15 multiplexer (018-004)
- MSP40 Mobile Sensor Platform
- An anti-vibration mounting kit *also required if you wish to mount the RM15-D on a PA20 frame.
- Geoplot 3.0 (012-005) is recommended for data transfer, processing and presentation of the data see separate data sheets for further details of these accessories. Recommended systems for a Basic Popular System or an Advanced Professional System are also available.
- The RM15-D is supplied as standard with an instruction manual, battery charger, data dump cable and a robust executive style carrying case.
