Contacting Conductivity Transmitters

The HCT63 Contacting conductivity transmitters combine modern technology with over 38 years of experience in building high quality sensors for liquid analysis to provide a range of competitively priced transmitters to cover a wide range of process applications.


Cable termination via detachable connectors, no need to open enclosure
Low voltage operation 15-30vDC
Simple intuitive programming
On Line multilingual help with text error messages

Custom IP66 enclosure

Available as head mounted or Wall mounted versions
Large back lit multifunction display
Displays conductivity, resistivity, ppm and temperature units
Dual isolated 4-20mA & relay outputs
Relays can be configured for on/off, time & pulse proportional
3 digital inputs to control specific functions
Supplied complete with sensor & ‘T’ piece. (Headmount version only)Purpose built detachable sensors for easy maintenance
Measured process & temperature can be displayed together
Meets current USP requirements
Full ultra pure water temperature compensation

Two different options of the HCT63 transmitter will be available with the base model offering a single industry standard 4-20mA output. The Advanced HCT63 will offer two 4-20mA outputs enabling the process temperature to be measured and transmitted as well as either the conductivity or resistivity value. The Advanced HCT63 model will also have 2 relay outputs for process control and also has 3 digital inputs for remote range changing via a plc.

Both of the HCT versions are available as head mounted transmitters with purpose built cells which offer cell constants of K=0.01 or 1.0 as well as being available as a wall mounting version. The wall mounting version of the HCT63 can be used with a detachable cable & separate LTH contacting conductivity cells with a cell constant of K=0.01, 0.1 and 1.0. This offers a wide operating range of conductivity measurement from ultra pure water (0.055μS) to solution concentration measurements (100mS). The transmitter can be set for single range, auto range or remote ranging via external digital inputs. The 2 off independent relay outputs that can be allocated to process measurement or temperature offer on/off control with variable hysteresis and time delays along with time and pulse proportional relay operation that is all configurable from the user menu. Relays can also be programmed to energise on a variety of different functions including errors, instrument status, e.g. off-line or calibration mode, or if a dose alarm time has been exceeded.

The relays can be configured for USP operation, which allows the transmitter to alarm when water is non-compliant. Up to 2 industry standard, isolated outputs provide retransmission of the measurement as 0/4-20 mA signals and can be configured to represent process measurement or temperature. Automatic temperature compensation is available as standard on all versions. For applications where temperature compensation needs to be applied to the measurement the linear slope is adjustable for changes due to dissolved salts and a fixed curve for the pure water contribution. The HCT63 is able to display the measured value either in conductivity, resistivity or total dissolved solids as well as displaying the process temperature.

The HCT63 has been designed with two levels of programme complexity to cater for both novice and experienced instrument operators. All cable connections to the HCT63 are by IP67 detachable connectors with no need to open the HCT63 enclosure. On-line HELP facilities consist of a series of text error messages which are displayed when programming is incorrect, or if a sensor is not reading a sensible value for the instrument set-up. A further enhancement is multi-level security, where day to day operator access can be limited to viewing data and settings only, while allowing full access to the instrument programmer.

Configuration data can be saved in one of two independent back-up locations, which can be used for fast reconfiguration, emergency restoration of settings, recovery after tampering by unauthorised operators, etc. Multilingual text displays can be selected with a choice of English, French, Spanish and Italian. The HCT63 can also display the current outputs as a bar graph as an alternative to showing a digital displayed value. It is possible to display either current output A, current output B, either current outputs alternating in the bar graph mode. The mode of display can be changed under the configuration menu. Both measurement inputs and current outputs can be individually calibrated from the front panel.

For applications requiring accurate measurements it is possible to calibrate the instrument and sensor to either the process conductivity or traceable solution. An off-line facility allows the instrument to be adjusted without disturbing external processes by de-energising the set point relays & holding the current output(s) at the last measured value.

The HCT63 also has a simulate mode to enabling the user to test the operation of the set point & current outputs

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Call us on +44 (0)1582 593693 or email sales@lth.co.uk to find out how we can help you.