arroyo instruments 274 TECMount Water Cooled Mount User Manual

: June 3, 2024
: arroyo instruments

Table of Contents

arroyo instruments 274 TECMount Water Cooled Mount
Introduction
Installation and Use
Connector Pin-Outs
Technical Specifications
Wetted Materials
Using the RTD on 150°C Versions
Operating at High Temperatures
Warranty
References
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arroyo instruments 274 TECMount Water Cooled Mount

Introduction

Thank you for choosing the 274 TECMount from Arroyo Instruments. The 274 TECMount is designed for high performance and long-term use. The 274 TECMount integrates a high-power Peltier cooler for precise control and substantial heating and cooling capacity for your powerful devices. The standard 274 TECMount has an operating range of -25°C to +85°C. Operation below the dew point requires a nitrogen-purged environment. The 274 TECMount requires water cooling for proper operation. For maximum performance, a chiller rated for at least 400 Watts or greater is recommended, but smaller chillers can be used for lower-power applications. The 5400-15-28 TECSource temperature controller is a good match for the mount delivering maximum performance and complete control across the 274 TECMount operating range.
The 274 TECMount also offers all the features you would expect from a modern diode fixture, including:

Hard nickel over the copper thermal plate.
Designed to be quickly integrated with Arroyo’s TECSource instruments.
Industry-standard D-sub connectors and pin-outs allow for quick integration into existing laser applications.
External sensor input for easy injection of on-board device sensor as sensor feedback.

Installation and Use

Connecting to the TEC Controller
First, connect the 274 TECMount to your temperature controller. Make sure the temperature controller’s current limit is set to a maximum value of no more than 16 Amps. Where possible, we recommend the use of Arroyo Instruments TEC cables. If you are using an Arroyo Instruments 5300 Series TECSource temperature controller, as 1262B TECSource cable is the recommend interconnect between the mount and controller. For the 5400 Series controllers, use the 1264-DB15 cable.

NOTE
Arroyo Instruments offers TEC cables designed to connect directly between our TECSource products. If you use your own cables, ensure the connections are properly made between the instrument and the mount, and that proper grounding techniques are used. The pin-out of the connectors can be found later in this document.

Connecting the water supply
The 274 comes with factory-installed brass barbs suitable for 3/8” I.D. hoses, but they can be replaced with any 1/8” NPT male fitting. It is recommended that when using the barbs, pipe clamps be used to secure the hose to the 274.

NOTE
Earth Grounding Considerations If your application requires that the cold plate be earth grounded, you should directly wire the cold plate to earth- ground.

Mounting Plate
The 274 TECMount has a breadboard configuration with M3 holes on 10mm centers. Optional blank adapter plates are available in several sizes (3.2”, 4.2”, and 5.2” square) to allow for custom mounting patterns or larger mounting surfaces. See the mechanical information below.

Connector Pin-Outs

Sensor Polarity and 4-Wire Connections
While the thermistor and RTD inputs are not polarized, when using a 4-wire RTD connection from the mount, it is important to properly connect the polarity of the sense wires to the sensor. Pins 7 and 14 should be one polarity (+) and pins 8 and 15 should be the opposite polarity (–). If polarities are not matched, the instrument will indicate a sensor error.

EXT Input and SENSOR Switch
The 274 features a SENSOR switch to quickly switch between internal and external temperature sensors. With the SENSOR switch in the INT position, the internal thermistor embedded in the cold plate is used to provide feedback for the temperature controller. With the SENSOR switch in the EXT position, the EXT+ and EXT- inputs on the Phoenix connector are connected to pins 7 & 14 Sensor+) and 8 & 15 (Sensor–). The 274 comes with one Phoenix 2-pin plug. Additional plugs can be ordered online at www.mouser.com or www.digikey.com, Phoenix part number 1803578.

Technical Specifications

274 TECMount

Wetted Materials

For purposes of evaluating galvanic corrosion, the following materials will make contact with the coolant:

Housing: Anodized AL 6061-T6
Fittings: UNS C36000 Brass
O-ring: EPDM

When using pure water as a coolant, distilled water is typically recommended unless your application dictates a different fluid.

Pressure Drop vs Flow Graph

The graph represents typical performance and will vary by flow rate and other conditions.

Configuring the Temperature Controller
When using an Arroyo Instruments temperature controller, the easiest method for configuring the controller to operate with the mount is to change the Mount setting in the menu by selecting 274 or 274-150, depending This will change the sensor settings and current limit to be appropriate for this mount. If you will be using a non-Arroyo controller, make sure to adjust the limits and sensor settings appropriately to ensure proper and safe operation of the mount.

Using the Thermistor on Standard Versions
The 274 LaserMount is equipped with a 10kΩ negative temperature coefficient (NTC) thermistor, specifically, the BetaTHERM 10K3A1. A thermistor works by translating temperature into resistance, with resistance decreasing as temperature increases (hence the ‘negative coefficient’). Below is the response curve of the thermistor:

As can be seen, by the graph, the resistance of the thermistor drops very quickly. In the typical control range (0°C to 40°C), typical 10K thermistors offer good sensitivity to changes in temperature, and this is the range in which most 10K thermistors are typically used. 10K thermistors can be used at much higher temperatures but will suffer poorer temperature stability performance because of the lower sensitivity. All Arroyo temperature controllers support operation using a 10μA or 100μA thermistor bias, which limits the upper control range to 450kΩ or 45kΩ, respectively. To minimize noise and maximize stability, you should select the highest current while still allowing you full operation across your required temperature range. The typical setting is 100μA, but your application will determine the actual needs.

The Steinhart-Hart Equation
As can be seen from the temperature versus resistance graph above, the resistance varies inversely with temperature in a non-linear fashion. This relationship can be accurately modeled by polynomial equations, one such being the Steinhart-Hart equation: The coefficients for the BetaTHERM 10K3A1 thermistor are:

A = 1.12924×10-3
B = 2.34108×10-4
C = 0.87755×10-7

These are the default coefficients for Arroyo Instruments temperature controllers but can be changed in the Sensor menu, or by selecting the appropriate 274 mounts from the Mount menu setting.

Using the RTD on 150°C Versions

The 274 TECMount can optionally be configured for up to 150°C operations. To support this high-temperature operation, an RTD sensor with a 0.00385 Ω / Ω / °C sensitivity is used. Like thermistors, RTDs also function by converting temperature into resistance, but unlike thermistors, RTDs increase in resistance as temperature increases. RTDs are also fairly linear devices, meaning they can be used across a much broader temperature control range. You can identify a 150°C configured 274 by its part number: a “-150” will be added to the end, for example, 274-150. According to IEC751, the resistance/temperature relationship is determined using one of two equations, dependent on the temperature or resistance value being measured. For resistances above the R0 value (resistance at 0°C, typically 100Ω, as is the case with the RTD used in the 274) of the RTD, the following equation is used:

R = R + AT + BT

Below R0, an additional term is added to the equation: In both of these equations, R0 is the resistance of the RTD at 0°C, and A, B, and C are the coefficients as defined by IEC751, through regression analysis, or by using the Callendar-van Dusen method. Not all Arroyo Instruments temperature controllers support RTD operation. Check with the factory for the recommended controller. In most cases, the 5400-15-28 is the recommended controller for the 274, although lessor-powerful controllers may be used, depending on the thermal load capacity required. For the Arroyo Instruments controllers that support RTD sensors, the default coefficients are not correct for this mount. They must be changed to use the0.00385 Ω / Ω / °C curve, which has the following coefficients:

A = 3.9080×10-3
B = -0.58019×10-6
C = -4.2735×10-12 R0 = 100

These coefficients can be changed in the Sensor menu, or by selecting the appropriate 274 mounts from the Mount menu setting.

2-Wire versus 4-Wire Measurements
One concern in using RTDs is their relatively low resistance (typically 100Ω at 0°C), and small Ω/°C. Because of these two factors, the resistance of the cable used to connect to the sensor can become a significant error in the sensor measurement. Most Arroyo Instruments controllers offer two RTD measurement modes: a conventional two-wire measurement mode, which is subject to this error, and a four-wire measurement mode that uses separate sensor and source lines to remotely sense the actual resistance of the RTD and eliminate the cable or connector resistances. When using 4-wire measurement mode, you must select ‘RTD (4-wire)’ as the sensor type, and then connect the Sensor+ and Remote Sensor+ at one side of the RTD, and Sensor– and Remote Sensor– to the other side of the RTD. Make these connections as close to the sensor as possible.
The drawings below illustrate how 2-wire and 4-wire connections work. Note that 4-wire measurements require all four wires to be brought through the cable to the mount. The 1262 TECSource cable carries this connection through to the mount, but the 1260B cable does not.

Operating at High Temperatures

The 274-150 (150°C-capable version) has additional requirements that should be considered when operating in the upper-temperature range:

The voltage requirements of the TEC increase significantly when operating at higher temperatures, so much so that the standard 5305 or 6300 Series controllers will be voltage limited when controlling the mount. To gain the maximum performance of the 274-150, the recommended controller the 5400-15-28 has a 15A / 28V output. Contact the factory for more details.
If the mount is heating when at high temperatures, if possible, raise the water temperature. By lowering the temperature difference between the water temperature and the plate temperature, the TEC will not work as hard, provide better plate uniformity as well as not require as much power to operate the TEC.

Mechanical Drawings

274 TECMount User’s Manual · Page 15

Optional Adapter Plates

274 TECMount User’s Manual · Page 17

Warranty

Arroyo Instruments warrants this product to be free from defects in material and workmanship under normal use and service for a period of one (1) year from the date of shipment. It does not apply when the product has been misused, altered or damaged by an accident or abnormal conditions of operation. If found to be defective during the warranty period, the product will either be repaired or replaced at Arroyo Instruments’s option.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. ARROYO INSTRUMENTS SHALL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES RESULTING FROM THE PURCHASE OR USE OF ITS PRODUCTS.

Service and Support
The 274 contains no user-serviceable parts. For service and support, contact your local distributor or Arroyo Instruments.