Sensor Inputs

The Model 336 offers four standard sensor inputs that are compatible with diode and RTD temperature sensors. The field installable Model 3060 thermocouple input option provides support for up to two thermocouple inputs by adding thermocouple functionality to inputs C and D.

Sensor inputs feature a high-resolution 24-bit analog-to-digital converter; each input has its own current source, providing fast settling times. All four sensor inputs are optically isolated from other circuits to reduce noise and to provide repeatable sensor measurements. Current reversal eliminates thermal electromotive force (EMF) errors in resistance sensors. Nine excitation currents facilitate temperature measurement and control down to 300 mK using appropriate negative temperature coefficient (NTC) RTDs. Autorange mode automatically scales excitation current in NTC RTDs to reduce self heating at low temperatures as sensor resistance changes by many orders of magnitude. Temperatures down to 1.4 K can be measured and controlled using silicon or GaAlAs diodes. Software selects the appropriate excitation current and signal gain levels when the sensor type is entered via the instrument front panel. The unique zone setting feature automatically switches sensor inputs, enabling you to measure temperatures from 300 mK to over 1,500 K without interrupting your experiment.

The Model 336 includes standard temperature sensor response curves for silicon diodes, platinum RTDs, ruthenium oxide RTDs, and thermocouples. Non-volatile memory can also store up to 39 200-point CalCurves for Lake Shore calibrated temperature sensors or user curves. A built-in SoftCal algorithm can be used to generate curves for silicon diodes and platinum RTDs that can be stored as user curves. Temperature sensor calibration data can be easily uploaded and manipulated using the Lake Shore curve handler software.

Temperature Control

Providing a total of 150 W of heater power, the Model 336 is the most powerful temperature controller available. Delivering very clean heater power, it precisely controls temperature throughout the full scale temperature range for excellent measurement reliability, efficiency, and throughput. Two independent PID control outputs supplying 100 W and 50 W of heater power can be associated with any of the four standard sensor inputs. Precise control output is calculated based on your temperature setpoint and feedback from the control sensor. Wide tuning parameters accommodate most cryogenic cooling systems and many high-temperature ovens commonly used in laboratories. PID values can be manually set for fine control, or the improved autotuning feature can automate the tuning process. Autotune collects PID parameters and provides information to help build zone tables. The setpoint ramp feature provides smooth, continuous setpoint changes and predictable setpoint approaches without the worry of overshoot or excessive settling times. When combined with the zone setting feature, which enables automatic switching of sensor inputs and scales current excitation through ten different preloaded temperature zones, the Model 336 provides continuous measurement and control from 300 mK to 1505 K.

Control outputs 1 and 2 are variable DC current sources referenced to chassis ground. Output 1 can provide 100 W of continuous power to a 25 Ω load or 50 W to a 50 Ω or 25 Ω load. Output 2 provides 50 W to 25 Ω or 50 Ω heater loads. Outputs 3 and 4 are variable DC voltage source outputs providing two ±10 V analog outputs. When not in use to extend the temperature controller heater power, these outputs can function as manually controlled voltage sources.

Temperature limit settings for inputs are provided as a safeguard against system damage. Each input is assigned a temperature limit, and if any input exceeds that limit, all control channels are automatically disabled.

Interface

The Model 336 is standard equipped with Ethernet, universal serial bus (USB) and parallel (IEEE-488) interfaces. In addition to gathering data, nearly every function of the instrument can be controlled through a computer interface. You can download the Lake Shore curve handler software to your computer to easily enter and manipulate sensor calibration curves for storage in the instruments non-volatile memory.

Ethernet provides the ability to access and monitor instrument activities via the internet from anywhere in the world. The USB interface emulates an RS-232C serial port at a fixed 57,600 baud rate, but with the physical connections of a USB. It also allows you to download firmware upgrades, ensuring the most current firmware version is loaded into your instrument without having to physically change anything.

Each sensor input has a high and low alarm that offer latching and non-latching operation. The two relays can be used in conjunction with the alarms to alert you of a fault condition and perform simple on/off control. Relays can be assigned to any alarm or operated manually.

The ±10 V analog voltage outputs on outputs 3 and 4 can be configured to send a voltage proportional to temperature to a strip chart recorder or data acquisition system. You may select the scale and data sent to the output, including temperature or sensor units.

Configurable Display

The Model 336 offers a bright, graphic liquid crystal display with an LED backlight that simultaneously displays up to eight readings. You can show all four loops, or If you need to monitor one input, you can display just that one in greater detail. Or you can custom configure each display location to suit your experiment. Data from any input can be assigned to any of the locations, and your choice of temperature or sensor units can be displayed. For added convenience, you can also custom label each sensor input, eliminating the guesswork in remembering or determining the location to which a sensor input is associated.

4 input/output display

Four Input/Output Display with Labels
Standard display option featuring all four inputs and associated outputs.

2 input/output display

Two Input/Output Display with Labels
Reading locations can be user configured to meet application needs. Here, the input name is shown above each measurement reading along with the designated input letter.

Intuitive Menu Structure

Intuitive Menu Structure
Logical navigation allows you to spend more time on research and less time on setup.

Use Additional Input Types with Option Cards

The field installable input option cards add additional input types. The Model 3060 adds thermocouple capability. The Model 3061 adds capacitance sensor inputs. The Model 3062 adds 4 Cernox®/diode inputs. While the option cards can be easily removed, it is not necessary as the standard inputs remain functional when the options are not being used.