The MIDAS CTD is an accurate, robust CTD Profiler. As well as using Valeport’s high stability conductivity sensor, which maintains performance at extreme temperatures and pressures, the MIDAS CTD is fitted with a high accuracy 0.01% pressure sensor as standard. It also features our unique synchronised sampling technique to ensure that all sensors are sampled at exactly the same time for perfect profiles. Titanium construction and a variety of communications methods make the MIDAS CTD ideal for real-time or autonomous profiling in virtually all conditions.
Sensors The MIDAS CTD is fitted with Valeport’s high stability conductivity sensor, a high accuracy temperature compensated piezoresistive pressure transducer, and a fast response PRT temperature sensor.
Data Acquisition The MIDAS CTD uses the concept of distributed processing, where each sensor has its own microprocessor controlling sampling and calibration of readings. Each of these is then controlled by a central processor, which issues global commands and handles all the data. This means that all data is sampled at precisely the same instant, giving superior quality profile data.
Communications The instrument will operate autonomously, with setup and data extraction performed by direct communications with PC before and after deployment. It also operates in real time, with a choice of communication protocols for a variety of cable lengths, all fitted as standard, selected by pin choice on the output connector:
Standard RS232: Up to 200m cable, direct to serial port via USB adaptor
RS485: Up to 1000m cable, addressable half-duplex comms
Memory The MIDAS CTD is fitted with 16Mb solid-state non-volatile FLASH memory. Total capacity depends on sampling mode; continuous & burst modes have a single time stamp at the start of the file, trip mode (profiling) stores a time stamp with each reading. A single line of CTD data uses 6 bytes, and a time stamp uses 7 bytes.