Crimea-300 depth and temperature monitoring system for divers

The Crimea-300 system consists of two modules connected to each other over the RS-485 protocol. The pairing protocol is fully open, allowing the measuring module to be used without the interface module by connecting it directly to your own system.

The interface module is installed on the dive control console. It lets you monitor the current ambient temperature and the diver's depth, and calibrate the measuring module.

The measuring module is attached to the diver and performs the measurements

Purpose

Crimea-300 lets the operator at the dive control console see the depth and water temperature at which a diver is working. The measuring module is an absolute pressure and temperature sensor in a cast polyurethane housing measuring Ø21×50 mm, with no corrosive parts. It is rated for depths of up to 300 m (a pressure range of 0–30 bar), and the cable is 0.5 m long (can be changed by agreement).

How it works

Depth is not measured directly: the sensor determines the water pressure and temperature, and the module calculates depth from the water density that has been set. The pressure resolution is 4 mbar and the temperature resolution is 0.1 °C. The sensor comes in a UART or an RS-485 version and sends data on request or on its own, cyclically, using a simple NMEA-like ASCII protocol (9600 bit/s, 8N1). The Crimea-300 OS interface module displays depth, water temperature, absolute pressure and the calculated speed of sound. The screen is a character display of 4 lines of 20 characters with Cyrillic support and stays readable in bright light. The module can be calibrated to atmospheric pressure (Z0) and lets you set the water salinity from 0 to 40 PSU: 0 PSU is recommended for fresh water, and for the sea, the salinity typical of the local waters.

Compatibility and connection

The interface module works only with measuring modules in the RS-485 version: the line can be run in shielded twisted pair up to 600 m long. The module is powered from 4–12 V, draws at most 1.1 W and is operated with two momentary buttons. The measuring module can also be used without the interface module by connecting it to your own system over the open protocol.

Documentation

Sensor specifications and the protocol description are given in the Crimea-300 datasheet, and the interface module's parameters and setup in the Crimea-300 OS datasheet. Both are currently available in Russian; see also the English accessories section.