Hydrotech ZS Consulting

Water quality monitoring equipment, Hydrotech, Hydrolab, YSI, In-situ, Eureka, EXO, Sondes, Multiprobes, Sensors, Monitoring equipment, Hydrolab repair, YSI repair, Nitrate, Nitrite, pH, Dissolved Oxygen, Turbidity, Conductivity, Salinity


 Antifouling module compatible with all multiprobes 

LDM "Long-term Deployment Module” ( Antifouling )  Now available to 200 feet depth (LDM max)  

The newly patented anti-fouling module from HydroTech. (Patent number 7,437,248.)

The most powerful anti-fouling (micro-fouling and macro-fouling) system in the market - "no gimmicks"

No copper - no questionable chemicals

Compatible with all existing multiprobes from all manufacturers

Continuous deployment for one to three months in the worst conditions

Guarantees stable and accurate measurements for all sensors

Computer GUI will provide you with easy setup and maximum control flexibility

Keeps sensors protected at all times during deployment

SDI-12 ready

Designed with all USGS needs in mind

Can be used as an online underwater sampler with In-Situ measurement validated data

With the LDM, you can now deploy a multiprobes in a discharge area where bubbling water would normally affect the sensors operation.


LDM standard: 

Outer diameter: 4.5”/11.43 cm

Length without guard: 14”/35.56 cm

Weight: 7.4 lbs/3.35 kg (typical)

Computer Interface: RS-232 and SDI-12

Operating Temperature: 1 to 50° C

Maximum Depth: 25 feet / 7.62 m

Minimum water depth 2 feet

Can be deployed to 20 degree angle from ground surface.

Maximum water depth  for the standard LDM is 25 feet ( 7.62 m )

LDM Max: 

Maximum water depth for the LDM max is  200 feet (60 m)  eet ( 60 m.00 )     

Most common questions and answers:

Q: Can the LDM be used with any multiprobe?

A: Yes. The LDM is designed to work with any multiprobe from any manufacturer. The sample housing is multiprobe specific but it's field replaceable.

Q: Does the LDM require external power? 

A: Yes. The LDM requires a 12 Volt external power source.

Q: Does the LDM operate with data-loggers like Sutron and Handar? 

A: Yes. The LDM can communicate to any data logger that uses SDI-12 or RS232 communication protocols.

Q: Can the LDM operate in waters with high sediments ? 

A: Yes. The LDM has an optional sediment filter at the intake. The end user can use any type of filter based on the application

Q: Can the LDM be deployed at an angle ? 

A: Yes, the LDM can be deployed up to a 20 Degree angle from the ground surface.

Q: What is the maximum depth deployment for the LDM? 

A:   25 feet under water ( 7.62 m ) for “LDM standard” 

      200 feet under water ( 60.00 m ) for the “LDM max” 

Q: What is the minimum depth deployment for the LDM?   

A: 1.65 feet under water ( 0.5 m )

Q: How does the LDM work? 

A: The LDM has a valve, a pump, and a controller board inside. A measurement cycle has three phases:

Phase 1: Filling the sample housing. This is accomplished by opening a valve for a set duration inside the LDM. The hydrostatic pressure allows the water to flow via the intake through the valve then fill the sample housing.

Phase 2: Holding the water in the sample housing. The valve is closed and the water inside the sample housing is held for set duration.

Phase 3: Emptying the sample housing. The pump turns on and pumps the water from the sample housing through the side tube to the surface.

Q: What is the dual tube on the side of the LDM used for?  

A: One tube is used to vent the sample housing to the surface which allows the sample housing to fill using hydrostatic pressure only. The other tube is used to evacuate the water from the sample housing to the surface for data validation at the surface if neede.

Q: What materials are used in the LDM ? 

A:All housings are built with Grey PVC. The cable jacket is Polyurethane, the connectors are 3/16 stainless steel .

Q: Can the LDM be used in fresh and salt water? 

A: The LDM can safely be used in fresh, salt water, and any body of water that is compatible with PVC, Polyurethane, and 3/16 stainless steel

Q: Are the LDM connectors waterproof? 

A: The LDM under water connector is 100 % waterproof and designed to stay under water continuously. The DB9 surface connector is watertight only and cannot be submerged under water.

Q: Do you have any references for LDM users: 

A: Yes. Please contact HydroTech for a list of customer references list. 512-846-2893 or email [email protected]

P.O. Box 5520

Round Rock, TX 78683  

1700 Bryant Dr. suite 103

Round Rock, TX 78664


Telephone: 512-846-2893

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