TD301/TD303 – Depth & Temperature


  • Compact & robust design
  • Long term stability sensors
  • High memory capacity
  • Year-long battery capacity
  • Windows based software
  • Output in physical units
  • Online plotting
  • Burst mode: 5Hz
  • SAIV/Digi format output

  • Bathymetry
  • Temperature & depth profiles
  • Autonomous recording
  • R.O.V.
  • Towed systems


The TD301/TD303 are precision instruments measuring temperature and depth (pressure) in the sea, lakes, water reservoirs, groundwater, rivers and on R.O.V. etc. All settings like measuring interval, real time clock etc, are accessed via menu. The programmed settings and calibration coefficients are maintained in nonvolatile eeprom, and will not be
changed/lost if power is disconnected. The model TD301 has a built-in replaceable battery for self- contained recording applications. On/Off- switching is by a magnetic key or from keyboard. The model TD303 is for on-line applications with external power supply and has an extra feature of 5Hz sampling with programable output formats to suit the host unit. Both units have a built-in data memory "ring memory" where the oldest data will be overwritten when memory is full. Data are recorded in physical units and simultaneously transmitted via an RS232 I/O watertight connector for on-line use. Robustness and complete protection from leakage has been obtained by vacuum molding the electronic and all other components in solid polyurethane. A comprehensive PC-program is supplied with the units for easy communication, programming and presentation/processing of data. For remote readout and monitoring, the manufacturer offers several options: Communication Unit CU901, for two-way communication via Iridium satellite, GPRS with embedded web server, GSM and UHF/VHF. 

Absolute types: TD301A/TD303A
Reference type: TD301R 
Differential types: TD301D/TD303D


Ranges (absolute): 20, 50, 100, 200, 500...6000 dbar
Reference differential: 10,20,50,100 dbar. 10,20,50,100,200 dbar. Line max 2000 dbar
Resolution: 0.0001 dbar (m)
Accuracy: +/- 0.01% FS
Response time: 0.1 sec

Range: -2 to +40°C
Resolution: 0.001°C
Accuracy: +/- 0.01°C
Response time: < 0.2 sec

Memory CMOS SRAM: 44000 data sets of TD (ring memory)

Data Output: RS232 ASCII code. 1200-9600 baud. 1 start , 7 data, 1 stop even parity or
1 start, 8 data, 1 stop, no parity, selectable via menu

Programmable: 1 sec to 180 min
Burst mode: 5 Hz w/programmable data formats

Real time clock: +/- 2 sec/day


Material: Vacuum molded polyurethane and titanium

TD301:2 ea 3.6V lithium AA-cells. Recommended type:SAFT LSH 14500(Sufficient for 1.000.000 data sets)
TD303:External power supply 10-30 VDC

Current consumption:
Active:< 10 mA
Quiescent:< 50µA

Dimensions: TD301/303:Length 170 mm. Diam. 45 mm
Weight: TD301/303: In air: 0.5 kg. In water:, 0.3 kg.

Common: MiniSoft SD200W program Operating Manual
TD301: On/Off magnetic key, PC communication cable (2,5m)
TD303: Connector and 1.5m pigtail

Warranty: Two years against faulty materials and workmanship.

Download datasheet as PDF