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XBT/XCTD Converter

Product Code:TS-MK150N

A digital converter measurement device for eXpendable profiling systems

This device converts signals received from XBT/XCTD probes. It connects to a probe deployment device, such as a hand launcher, and to a computer in which the included specialized software has been installed.

MK150N digital converter(T.S.K)tsurumi-seiki

Main functions

  • Displays measurement data and graphs (real-time display, saved data display)
  • Data conversion (conversion of measurement data into physical quantities, conversion of data per 1m, header editing)
  • Calculates and outputs sound velocity and density

Specifications (Comparison of old product)

Item TS-MK150N TS-MK130(Old Product)
Size (W)320mm×(D)265mm×(H)46mm (W)330mm×(D)260mm×(H)100mm
Weight approx 3Kg approx 5kg
Power AC100V±10% 50/60Hz AC100V±10% 50/60Hz
Proper temperature 0~40℃ 0~40℃
Proper humidity 0~90%RH
(Assuming no condensation)
(Assuming no condensation)
Interface for PC connection USB2.0 RS-232C
Dedicated software
Microsoft Windows
Microsoft Windows 95/98/98SE/Me/NT/2000/XP


MK150N  front

MK150N  rear

Supported XBT Probe

Type Measuring Depth (m) Ship Speed (knots)
T-10 300 10
T-6 460 15
T-7 760 15
760 20
T-5 1830 6

Supported XCTD Probe

Type Measuring Depth (m) Ship Speed (knots)
XCTD-1N 1000 15
XCTD-2N 1850 3.5
XCTD-3N 1000 20
XCTD-4N 1850 6
AXCTD(For Airborne) 1000
  • The above specification values are reference values, and are subject to change without prior notice.

XCTD systems shipped from April 2021 have a new XCTD probe design.

New XCTD label

Please review the changes resulting from the changes to the XCTD’s circuit board and the procedures for checking and updating the Windows software in order to be able to use the new XCTD.


Inquiries regarding eXpendable systems

Please provide the following information when contacting us with inquiries.

  • Type of probe used
  • Serial number
  • Converter/launcher configuration
I can't save data.

Computer software data save location settings for the MK-130

When measurement has been completed, the computer software included with the MK-130 XBT/XCTD digital converter automatically saves the data to a user-specified folder. However, when the software installation process ends, the data save folder location will not yet have been specified.

If measurement is performed without specifying the data save folder location, when measurement ends a message will be displayed stating that the data is being saved, but the measurement data will not actually be saved. After installing the software, always specify the folder to which data is to be saved. The data save folder location can be set by clicking on the “Option” tool icon.

The values indicated by the probe don't change even though it is in the water.

XBT probe: Ground connection issue

If the system is not correctly grounded, data may not be properly relayed between the XBT probe and the converter. This may cause issues such as probe values not changing or noise within the data. Even if measurement is performed, if the device is insufficiently grounded, data values may be unstable. Securely connect the converter’s ground terminal to a well-grounded object.


XCTD probe battery issue

The XCTD probe contains a battery. The XCTD is designed such that it does not consume battery power until measurement begins. However, the amount of charge in the internal battery may fall before use as a result of self-discharge or probe storage conditions. When measurement begins, the probe will turn on and begin consuming battery power. When canceling probe deployment, always click “Abort” before disconnecting the probe. If deployment is aborted, the probe will be turned off, reducing battery consumption.


XCTD probe battery capacity

When the XCTD probe is manufactured, it has a battery capacity of approximately 20 minutes. Battery charge will be consumed when measurement begins. Therefore, if the probe is deployed 15 minutes or more after starting measurement, even if there are no probe battery problems, the battery may run out before or during measurement. Please check the probe measurement time and the amount of remaining battery charge.


Battery self-discharge and XCTD probe storage conditions

The XCTD probe battery may experience significant self-discharge depending on its storage conditions. Normally, if stored at room temperature, the probe may be stored for approximately two years from the date of purchase. However, please be aware that the battery level may be low if the probe has been in storage for a long period of time or if it has been stored at temperatures that are far above or below room temperature.

There is noise in the measurement data.

Data value instability as the result of outside noise

The XBT/XCTD system performs measurement using weak electrical signals. In some usage environments, outside noise may cause the system to operate abnormally or produce unstable measurement data. If this occurs, please double-check the ground connection. Also, please note that wireless devices may be sources of electrical noise that affects the system.


Probe wire-related issue

If the probe wire is broken during measurement, the following problems may occur.


  •  Values do not change at all beyond a certain depth
  • Measurement values for depths beyond a certain depth are not shown on-screen
  • There is noise in the measurement data

The probe is designed such that the wire is not broken by the force applied to the wire by the speed of the dropping probe or the speed of the boat. However, if other forces place stress on the wire, the probe wire may be severed.


The main causes for probe wires being severed include the following.


  • The wire becomes entangled in the ship’s propeller
  • The probe wire scrapes against the ship’s body
  • The probe wire strikes an obstacle while dropping from its deployment point to the surface of the water

When deploying the probe, select a location and time where factors such as these will not affect the wire. Even if the wire is not severed, if it scrapes against the ship, etc., this may result in abnormal data measurements. In situations such as these, deploy the probe in a position in which the wire will not scrape against the ship.


Hand launcher connector problems

When measurement is being performed, probe signals are sent to the converter via the launcher. If there is a problem with the electrical signal route within the launcher, it may cause various problems, such as measurement being interrupted, noise appearing in the data, or measurement not beginning when the probe is deployed.


If the cable connector is broken or the connector terminal is damaged, the launcher will need to be repaired. The aforementioned problems may also occur even if there are no problems with these components. Please check the following as well.


1、Is the probe connection pin dirty?

The probe connection pin is the point where the probe signal terminal comes in direct contact with the launcher. If the probe connection pin is dirty, it may not be possible to establish a proper connection between the launcher and the probe. Wipe the probe connection pin clean and reconnect it to the probe.


2、Is there a probe connection pin connection issue?

The end of the probe is heavy, so the probe may not be mounted in the launcher correctly.


Probe mounted correctly

Probe mounted correctly

Probe not mounted correctly

Probe not mounted correctly


If this occurs, mount the probe in the launcher with the two pointed downward.


Probe setting method

Probe setting method


Values do not change at all beyond a certain depth.

Abnormal signal when the probe reaches the sea floor

If the probe reaches the sea floor before it completes measurement, it may produce abnormal values.


1、Values do not change at all beyond a certain depth.

2、An extremely large amount of noise is measured beyond a certain depth.


When the probe is deployed, it measures water temperatures and electrical conductivity values with the sensor at the front end of the probe. Depth, however, is measured by measuring the amount of time that has elapsed after the probe was detected to have entered the water. Therefore, if the probe reaches the sea floor, etc., it may no longer actually be dropping, but measurements will continue to be taken at the actual location of the probe.


An I/O error has occurred during the XCTD measurement preparation stage.

The software does not function correctly when performing XCTD measurement using the MK-130 converter

I/O errors have been confirmed as occurring in some computer environments when performing XCTD measurement with the MK-130.

These problems have been confirmed as occurring when the MK-130 software is used on certain computers and in certain operating system environments. We have confirmed that these problems can be prevented with partial software modifications in some computer environments. Please check the following.


  • Are the computer and the MK-130 software operating correctly?
  • Are all cables connected correctly?
  • Is the MK-130 functioning correctly?

If all devices and components are functioning correctly but you continue to experience problems, please contact us with information regarding your computer environment and OS environment. If the software does not function correctly due to reasons other than those indicated above, the problem may be in your computer environment. If you are installing MK-130 software in your computer for the first time, always confirm operation using a test probe, etc., before performing measurement.