Libratherm Instruments Private Limited

Description:

Libratherm offers Microcontroller based Humidity and Temperature Controller Model HTC-3003 with input and output suitable for measuring and controlling the T and RH of stability or environmental test chambers or walk-in chamber. These chambers are mainly used in Pharma, Petroleum, Chemical and Food Industries to test and store the product / sample under the desired simulated and control climatic environment.

The controller HTC-3003 accepts input from the standard T + RH sensors consisting of (Pt-100) temperature sensor and the capacitive type RH sensor or from direct T + RH sensor / transmitter. (The suitable sensors or transmitters of international brands can be used along with this controller).  The input signal is processed by 16 bit ADC for very accurate and stable display. The time tested PID algorithm gives accurate control of Temperature and %Rh. The single controller has advantage of tracking and synchronizing the two different process parameters over individual control for temperature and %RH.

In model HTC-3003, the process values and set values are displayed simultaneously on 4 independent 4 digit 7-segment Red / Green LED displays. The real time is displayed on an extra 4 digit display.

Since these controllers are basically designed for the stability chambers, the accurate control of temperature and humidity is achieved by operating the air heater (for Dry heat) and the boiler heater (for Moisture or water vapour) in the PID control action, and the compressor (for low temperature) is operated in ON/OFF action with user programmable time delay facility. Since the compressors are not required to be kept ON above certain level of temperature, the user selectable mode is provided to program the compressor operation in AUTO, Continuous ON or Continuous OFF mode. To de-humidify the system, an extra ON/OFF output is provided to operate either the same compressor or an extra compressor – with time delay function.  All the control outputs are in the form of SSR drivers of (0 to 12) VDC pulse to control the Air heater, boiler heater and compressor and dehumidifier. In case of water level low, the audible alarm is generated and heaters are turned off to prevent dry run and safety.

HTC-3003 has many other useful features:

in-built real time data storage facility, which can be retrieved on demand or can be down loaded on to a computer or on a printer for hard copy via the built in serial printer port. The storage capacity depends on the logging time. Maximum 3600 records can be stored which can be printed in OFF line mode. The battery backed non-volatile flash memory is used for the data storage.

HTC-3003 accepts 2 nos. of external potential free contacts (DI) to detect the water level of the boiler used for generating the steam or moisture and to monitor the status of the front door of the chamber – through limit switch contacts.  

HTC-3003 is ready with the serial communication port RS 485 with RTU modbus protocol for interfacing to the computer for data logging and storage.

Features:

• Microcontroller based design.
• Easy front panel keyboard programmable.
• Independent 4 control outputs for Temperature/%RH control (4 x DO)
• Digital input for water level, door switch etc… (2 x DI)
• User programmable alarm limits with auto snooze facility.
• PID or ON/OFF control action for Air heater, Boiler heater and ON/OFF control action for Compressor with programmable time delay.
• Direct dot matrix serial output for EPSON printer model LX-300+ or Equivalent.
• RS-485 port for computer interface.
• User friendly and expandable Window based PC software.

Model Wise Description:


Description:

Libratherm offers new models of Temperature and Humidity indicator & Controller Model DTH-966, designed using the latest high-speed microcontroller. This controller is most suitable for Hatchery Incubator and other similar applications.

DTH-966-A: This models accepts input from standard T + RH sensor (model HTS-220). The instrument displays the temperature in the range of 0.0 to 60.0oC  and humidity in the range of 0.0 to 100.0 % RH on 4 digit 0.5” 7-segment Red / Green LEDs. It offers 4 relay outputs, 3 relays are operated with respect to Temperature and 1 relay is operated with respect to Humidity. 4 independent set points can be programmed using front panel key boards. 

Features:

• Microcontroller based design.
• Elegant appearance, easy to operate and compact in size.
• Highly accurate and sturdy in operation.
• Dual display for simultaneous indication of T and RH.
• Field proven Algorithm, tested successfully for various HVAC control applications.

Model Wise Description:


Description:

Libratherm offers two new models of Temperature and Humidity indicator & Controller Model DTH-723 and DTH-966, designed using the latest high-speed microcontroller. These controllers are most suitable for Stability Chamber, HVAC and other similar applications.

DTH-966-C: This model accepts models accepts inputs from standard T + RH sensor or transmitter (as given in table below. The instrument displays the temperature in the range –40.0 to 60.0 oC and humidity in the range of 0.0 t o 100.0 % RH on 4 digit 0.3”/0.5”7-segment Red/Green LED display. The outputs are made available for controlling temperature and %RH in stability chamber, walk in chamber or other similar systems. The DC pulse outputs for a) controlling Air heater in PID/On-Off mode b) Cooling compressor with time delay in AUTO/ON/OFF mode and c) Boiler Heater in PID/On-Off mode. d) Common Alarm output for Temperature and humidity both. This model also accepts 2 nos. of external potential free contacts to detect the water level of the boiler used for generating the steam and to monitor the status of the front door of the chamber – through limit switch contacts. The Door operating command can be issued externally from the PC .

Software and Touch Screen Panel: To interface DTH-966 with the computer for data acquisition, PC based 21 CFR – part 11 complied Software is also available. This software allows user to operate and set the control parameters, view the temperature and %Rh data with real time in the form of graph or in the form of Table. Software versions are available to acquire the datas from single controller or from multiple controllers (2 to 32). Touch screen panel (MMI) can also be interfaced with this controller for ease of operation and online viewing of process parameters with graphical representation. Standard or customized softwares can be provided as per the customer’s requirement. Please write to us for more details.

Features:

• Microcontroller based design.
• Elegant appearance, easy to operate and compact in size.
• Highly accurate and sturdy in operation.
• Dual display for simultaneous indication of T and RH.
• Field proven Algorithm, tested successfully for various HVAC control applications.

Temperature / Humidity Controller for Hatchery Incubator
(Microcontroller based - 6 Set Points)

Description:

Libratherm offers new model (Model HTC-966) which is specially designed for the Hatchery Incubators / Ovens. It is made using the high speed microcontrollers with 12bit ADC for very accurate measurement of temperature and humidity using the dry and wet bulb RTD (Pt-100) sensors. It is easy and user friendly to program to operate.

The best part of this controller, is that, user can program 6 different set points, out of which 3 are with respect to dry sensor, 1 is with respect to both dry and wet sensor and 2 are with respect to wet sensor. Against each set point, the controller gives the six optically isolated control outputs in the form of DC SSR pulse. These pulses can be used to drive external electromechanical relay module or SSR module. Libratherm offers, both Relay module and SSR module rated for 10A @ 230VAC.

As per the requirement of the hatchery incubator/oven, the temperature is displayed in oF with +/- 0.1oF accuracy / resolution. The six outputs can be programmed as per the requirement and can be used to control heaters, fans, pumps and solenoid valve, as shown in the above diagram. In the event of deviation of dry or wet bulb temperature from the set values, the audio/visual alarm signal is activated, so that corrective action can be taken by the operator.

To facilitate user to record the temperature on the computer, RS485 digital port is available from the controller. Libratherm provides, required interfacing PC software.

Features:

• Highly accurate and sturdy in operation.
• Elegant looks, Very easy to operate.
• Accepts RTD (pt-100) 2 or 3-wire input.
• Control output of Relay or DC pulse or TRAIC.
• Programmable Hysterisis.
• User configurable output up to 4 or 6 set points.
• Operates on Universal supply of 90 to 250 VAC, 50/60 Hz.

Applications:

• Hatchery Incubator / oven
• Heater bank selection
• Star delta changeover
• Process industry
• Plastic / Packaging industry

Product Description:
Libratherm offers Economical, rugged, reliable and fairly accurate T + RH sensor (imported from Japan) model HTS-220 / HS-220 for measuring Temperature and Humidity in the atmosphere / environment / AHU or DHU Chamber. The sensor is easy to mount and comes with 2 meter PVC color coded multicore cable. The sensor is housed in a rugged ABS enclosure. For Indication purpose, external digital display can be used with calibrated scale as given below in the technical specifications.

Applications:

HVAC / AHU / DHU

Green House, Ware House,

Server Room, Data Centre, Textile

Pharma Labs, Stability Chamber, Humidifier

Features:

• Microcontroller based design.
• Elegant appearance, easy to operate and compact in size.
• Highly accurate and sturdy in operation.
• User programmable settings
• Dual display for simultaneous indication of T and RH.
• Field proven Algorithm, tested successfully for various AHU / HVAC control applications.

Description:
Libratherm offers PID controller model DTH-966-AHU for controlling temperature (T) and relative humidity (Rh) for the AHU and other similar HVAC applications.  For the proper functioning of the Air Handling unit, it is required to monitor the T and Rh of the Air being supplied to the room or the hall. The T and Rh values are to be compared with the desired set values and based on the error between the process values and set values the operation of the hot/cold water valves/damper Actuators, heaters, are controlled to maintain the T and Rh in the Air flow.

This model DTH-966-AHU accepts inputs from standard T + RH sensor or transmitter (as given in the table below). The instrument simultaneously displays the temperature in the range -40.0 to 60.0oC and relative humidity in the range of 0.0 to 100.0% RH. The PID outputs are available for controlling temperature and %RH in the form of 4-20mA and /or in the form of DC pulses. Common or individual High and Low alarm output for Temperature and humidity can be provided as per user’s requirement. To meet specific AHU control application, the 3 way valve can be operated by 4-20mA proportional PID in direct action to control the temperature and for controlling RH, the DC pulse output is available, which can be used to control AC or DC operated solenoid valves or to control the heating for evaporation of moisture using Libratherm make - single or three phase thyristor control. RS485 serial port is available for interfacing to DCS or PLC.

Features:

• Microcontroller based design.
• Elegant appearance, easy to operate and compact in size.
• Highly accurate and sturdy in operation.
• User programmable settings
• Dual display for simultaneous indication of T and RH.
• Field proven Algorithm, tested successfully for HVAC control applications

Description:
Libratherm offers PID controller model DTH-966-DHU for controlling temperature (T) and relative humidity (Rh) for the AHU and other similar HVAC applications.  For the proper functioning of the Air Handling unit, it is required to monitor the T and Rh of the Air being supplied to the room or the hall. The T and Rh values are to be compared with the desired set values and based on the error between the process values and set values the operation of the hot/cold water valves/damper Actuators, heaters, are controlled to maintain the T and Rh in the Air flow.

This model DTH-966-DHU accepts inputs from standard T + RH sensor or transmitter (as given in the table below). The instrument simultaneously displays the temperature in the range -40.0 to 60.0oC and relative humidity in the range of 0.0 to 100.0% RH. The PID outputs are available for controlling temperature and %RH in the form of 4-20mA and /or in the form of DC pulses. Common or individual High and Low alarm output for Temperature and humidity can be provided as per user’s requirement. To meet specific DHU control application, the 3 way valve can be operated by 4-20mA proportional PID in direct action to control the temperature and for controlling RH, the DC pulse output is available, which can be used to control AC or DC operated solenoid valves or to control the heating for evaporation of moisture using Libratherm make - single or three phase thyristor control. RS485 serial port is available for interfacing to DCS or PLC.