RH PT12 Manual

Hide thumbs

Table Of Contents

Table of Contents

Quick Links

Download this manual

PT12

Manual

RH Systems, LLC

1225 W Houston Ave.,

Gilbert AZ, 85233

Table of Contents

Need help?

Do you have a question about the PT12 and is the answer not in the manual?

Questions and answers

Summary of Contents for RH PT12

Page 1 PT12 Manual RH Systems, LLC 1225 W Houston Ave., Gilbert AZ, 85233 ...
Page 2: Table Of Contents
Introduction ................................ 5 Quick Start / Initial Setup ............................ 6 Connecting a Temperature Probe ......................... 6 Starting Up the PT12 .............................. 7 Obtaining a Reading ............................ 7 Plotting Temperature ............................ 9 Operation ................................ 1 0 ...
Page 3 Probe Commands .......................... 4 3 Calibration ................................ 4 5 Uncertainty ................................ 4 6 Specifications ............................... 4 7 Document History .............................. 4 8 FOR SUPPORT, PLEASE EMAIL SUPPORT@RHS.COM OR CALL (480) 926‐1955 WITH TECHNICAL OR CALIBRATION QUESTIONS. PT12 Manual 7/20/2021 Page 3 of 48 ...
Page 4 Introduction PT12 Manual 7/20/2021 Page 4 of 48 ...
Page 5: Introduction
Introduction INTRODUCTION The PT12 is a highly precise and stable platinum resistance thermometer (PRT) based multi‐channel temperature measurement system. Using a custom designed high precision measurement circuit with full current reversal and multiplexed sampling, the PT12 provides 12 channels of low uncertainty temperature data for validation and calibration. Using one of three automatic or user selectable currents, the PT12 repeatedly scans all 12 channels. Employing a full reversal current source, the PT12 eliminates polarity sensitive errors normally inherent to DC measuring techniques. Accuracy is further enhanced by referencing all measurements to a series of high accuracy, temperature stable internal reference resistors. The integrated firmware allows each channel to be individually programmed with ITS‐90 or Callendar‐Van Dusen (CVD) coefficients for direct conversion of resistance measurements to temperature. It incorporates a full color, pinch zoom touch screen as the user interface. Although not required for operation, the PT12 may also be connected to a PC over an RS‐232 or USB interface. PT12 Manual 7/20/2021 Page 5 of 48 ...
Page 6: Quick Start / Initial Setup
Quick Start / Initial Setup QUICK START / INITIAL SETUP The quick start is intended to get you up and running quickly. For additional information see section 4 Operation. CONNECTING A TEMPERATURE PROBE Select any of the supplied probes and connect it to any desired channel (the remainder of this section will assume channel 5). When inserting the plug, ensure the red dots line up. PT12 Manual 7/20/2021 Page 6 of 48 ...
Page 7: Starting Up The Pt12
Starting Up the PT12 STARTING UP THE PT12 Plug in the included AC power adapter to a 110‐240VAC outlet. Plug the round connector of the power adapter into the back of the PT12. A splash screen should appear in about 15 seconds and the machine will fully boot within about 30 seconds. Power (12V DC, 3A) USB Flash Drive USB Serial RS‐232 ...
Page 8 Starting Up the PT12 To select a display mode, tap the desired icon. The menu will hide, and the new display mode will appear. For this quick start example, select the top left display mode icon (this is the temperature graph display mode). For more information see section 4.3 Navigating the User Interface. PT12 Manual 7/20/2021 Page 8 of 48 ...
Page 9: Plotting Temperature
Starting Up the PT12 PLOTTING TEMPERATURE To add a probe’s value to the graph, tap the appropriate probe (probe 5 in this case) on the top portion of the screen. The probe’s recent data will be plotted on the graph. To ensure that the data is visible, tap the Show All graph buttons, and the Continuous Update button to enable them. When enabled, they are highlighted in light blue. Drag a single finger on the graph to scroll in any direction. Use two fingers for pinch‐zoom operation. For additional information on graph functions, see section 4.3.1 Temperature Graph Display Mode Note: The graph only retains the last 48 hours of data, while the log file holds all the data since the last power cycle or when logging was last toggled on. See sections 4.5 File Manager and 4.6 System Info. ...
Page 10: Operation
Operation OPERATION The PT12 measures temperature by ratiometric comparison of the unknown resistance of a temperature probe to a series of temperature stable precision reference resistors. Through custom selection of the four reference resistors, the PT12 operating range and precision can be tuned for either 25 Ω PRTs or 100 Ω PRTs. Alternatively, it can be customized to cover both ranges with slightly less overall precision. (For more information on customization, contact RH Systems). The PT12 supports three distinct current modes which can be manually or automatically selected. The three current modes available are approximately 0.3 mA, 0.6 mA, and 1 mA. The PT12 will attempt to get the most accurate reading possible when utilizing auto current mode. CONNECTING TEMPERATURE PROBES There are 12 LEMO connectors (one per probe) on the PT12 and any number of probes (between 1 and 12) may be connected in any order at any given time. To connect a probe, ensure the red dots between the plug and receptacle are aligned, then push to connect. Pulling up on the body of the plug releases the catch, allowing the probe to be removed. Once inserted, the PT12 will automatically detect the probe and determine if it is a smart probe (with internal configuration memory) or a basic probe (without any memory). PT12 Manual 7/20/2021 Page 10 of 48 ...
Page 11: Basic Probes
Operation 4.1.1 BASIC PROBES Basic probes do not have internal memory and use the channel’s configuration for coefficients. If you move a basic probe from one channel to another, you will have to manually reenter the probe coefficients. Pins 1 and 6 are jumpered together inside the LEMO plug to indicate a basic probe. Jumper Wire LEMO F66.1B.306 Basic Probe Image 3.1.1 PT12 Manual 7/20/2021 Page 11 of 48 ...
Page 12: Smart Probes
Operation 4.1.2 SMART PROBES The LEMO connector of each smart probe is embedded with a Maxim Integrated DS28EC20 ‐ 20Kb 1‐Wire EEPROM chip. This memory chip holds the probe’s coefficients, serial number, and calibration date. When a smart probe is plugged in, the PT12 automatically detects it and extracts configuration information from the chip. Manual entry of coefficients is not required as the configuration information travels with the probe regardless of which channel it’s plugged in to. DS28EC20 LEMO F66.1B.306 Image 3.1.2 4.1.3 USER‐SUPPLIED PROBES User supplied probes may be utilized by wiring them to a LEMO connector (part #FGG.1B.306). To create a basic probe, short pin 1 to pin 6. To create a smart probe, insert a Maxim Integrated DS28EC20 with pin 1 of the chip to pin 1 of the LEMO and pin 2 of the chip to pin 6 of the LEMO. Pin 3 of the chip is unused and should be cut off. See Image 3.1.2 above. Both smart and basic probes will require an initial entry of coefficients. Upon saving, the smart probe coefficients will travel with the probe. Basic probe coefficients will be retained in the PT12 channel. ...
Page 13: Channel Measurement Rate
CHANNEL MEASUREMENT RATE It takes approximately 90 msec per reading for each of the attached probes and each of the four internal reference resistors. Meaning, if twelve probes are attached, the total measurement time to update all twelve channels and the four reference resistors is just under 1.5 seconds. If fewer probes are plugged in, unused channels are automatically skipped, increasing measurement frequency. For example, with only one attached probe, the approximate update rate would be less than 0.5 seconds. NAVIGATING THE USER INTERFACE The PT12 has a touch screen interface that supports tap, pinch/zoom, swipe, and long press. They each have different functions and are supported on various display modes. The PT12 has several different display modes. It will power up in the previous mode that was displayed on shut down. To change display modes swipe with a finger from the left‐hand side. This brings up a menu of available display modes. Swipe To select a display mode, tap the desired icon. The menu will hide, and the new display mode will appear. ...
Page 14: Temperature Graph Display Mode
Operation All Resistances: Shows a 2x6 grid with the resistances of all twelve probes. 4x Numeric: Shows a 2x2 grid with the temperatures and resistances of any four selected probes. 2x Numeric: Shows temperatures and resistances in a large font for any two selected probes. Combo: Shows up to twelve connected probe temperatures on one side, a mini graph, and a large numeric value (temperature and resistance) for any single probe selected. Probe Status: Shows the probe connection status of each channel of the PT12. 4.3.1 TEMPERATURE GRAPH DISPLAY MODE To add a probe to the graph, tap on its numeric value. The numeric value will be outlined in a unique color, and the temperature plot will appear on the graph in that same color. NOTE: The graph only retains the last 48 hours’ worth of data, while the log holds all the data since the last power cycle or when logging was last toggled on. PT12 Manual 7/20/2021 Page 14 of 48 ...
Page 15: Scrolling The Graph
Operation SCROLLING THE GRAPH To scroll the graph, drag a finger in any direction. Alternatively, to scroll a single axis, drag within the axis area. PT12 Manual 7/20/2021 Page 15 of 48 ...
Page 16: Zooming The Graph
Alternatively, to zoom a single axis, long press on the axis area then drag. For y‐axis, drag up or down to zoom in or out. For x‐axis, drag right or left to zoom in or out. AXIS CONTROL Show All (x‐axis): While the button is selected the x‐axis will be scaled to show all data. Show All (y‐axis): While the button is selected the y‐axis will be scaled to show all data. Fixed y‐axis (semi‐auto): While the button is selected the y‐axis is fixed. If the data goes out of bounds the y‐axis automatically adjusts to fit the data. Locked y‐axis: While the button is selected the y‐axis remains exactly as shown without any auto adjustment. X‐axis Width: Fixes the width of the x‐axis to the specified period of time. Scrolling does not affect this value however, zooming overrides this value. The numeric value displays in hours, minutes, or seconds based on its associated drop‐down menu. Continuous Update: While the button is selected, the graph will always display the most recent values, scrolling the time axis as required. Manually scrolling or zooming will disable this button. PT12 Manual 7/20/2021 Page 16 of 48 ...
Page 17: Graph Statistics
Operation GRAPH STATISTICS To display numerical statistics of any currently graphed data, long press and drag the box to highlight the graph data you wish to analyze. After releasing, the statistics will be shown above the graph. Scroll the statistical data left or right to display more information. PT12 Manual 7/20/2021 Page 17 of 48 ...
Page 18: Resistance Graph
Display Mode, with the exception that values shown and graphed are probe resistances rather than temperatures. 4.3.3 ALL TEMPERATURE DISPLAY MODE The All Temperature Display Mode simultaneously shows all twelve temperatures in the largest font possible. Unconnected channels appear with blank values. PT12 Manual 7/20/2021 Page 18 of 48 ...
Page 19: All Resistance Display Mode
Operation 4.3.4 ALL RESISTANCE DISPLAY MODE The All Resistance Display Mode simultaneously shows all twelve resistances in the largest font possible. Unconnected channels appear with blank values. 4.3.5 NUMERIC 4X DISPLAY MODE The Numeric 4x Display Mode shows any combination of four individually selectable channels. Each of the four channels may be selected to show temperature or resistance in a large font while showing the opposite in a smaller font. PT12 Manual 7/20/2021 Page 19 of 48 ...
Page 20: Numeric 2X Display Mode
4.3.6 NUMERIC 2X DISPLAY MODE The 2x Numeric Display Mode shows any combination of two individually selectable channels. Each of the two channels may be selected to show temperature or resistance in the largest possible font. Operation is identical to section 4.3.5 Numeric 4x Display Mode. PT12 Manual 7/20/2021 Page 20 of 48 ...
Page 21: Combo Display Mode
Operation 4.3.7 COMBO DISPLAY MODE The Combo Display Mode shows up to 12 connected probe’s temperatures on one side, a mini graph, and a large numeric value (temperature and resistance) for any single probe selected. The functions of the mini graph operate identical to the graph in section 4.3.1 Temperature Graph Display Mode. Although the graph is physically smaller, it is the same graph as on the other display modes. To add a channel to the graph, tap the channel value. The large numeric value above the graph operates identical to a single item from section 4.3.5 Numeric 4x Display Mode. This display only shows up to 10 of the connected probes simultaneously. Scroll the numeric data section to see others. PT12 Manual 7/20/2021 Page 21 of 48 ...
Page 22: Probe Status Display Mode
Operation 4.3.8 PROBE STATUS DISPLAY MODE The Probe Status Display Mode shows the current probe status of each of the twelve channels. PT12 Manual 7/20/2021 Page 22 of 48 ...
Page 23: Changing Displayed Units Of Measurement
Operation 4.3.9 CHANGING DISPLAYED UNITS OF MEASUREMENT The available temperature display units are °C, °F, °R , and K. To change the displayed units of measurement, swipe in from the left on any display mode and tap the desired unit on the bottom of the menu. Changing units is common to all probes, meaning all temperatures will be displayed in the new units. However, for uniformity and consistency, temperature is always logged to file in °C and the serial port interface will always respond in °C regardless of displayed unit selection. Resistance is always in Ω. 4.3.10 CHANGING NUMBER FORMAT To change the number format of displayed values, long press on a numeric value to bring up the Change Number Format button. Tap the change number format button which brings up the number format screen: PT12 Manual 7/20/2021 Page 23 of 48 ...
Page 24: Configuring The Probes
Operation Choose a desired number format and tap OK for the single item, or Apply to All to apply the format to all PT12 displayed values. CONFIGURING THE PROBES To configure the probes, open the settings menu by swiping in from the left, then tap the settings button on the lower section of the menu. PT12 Manual 7/20/2021 Page 24 of 48 ...
Page 25: Averaging
Operation In the settings menu that appears, select the appropriate channel for the probe you wish to configure. NOTE: Each probe has its own set of coefficients, averaging, current mode, etc. and each of them need to be saved individually. 4.4.1 AVERAGING Probe averaging uses a weighted response low pass filter. To change averaging, tap on the text box. The on‐screen keyboard will appear and allow entry of a new value. You must press enter to confirm the change. Reasonable averaging range is 0 to 100. 0=no averaging, every reading is new. 100=slower reaction, longer stabilization time but with significant noise reduction. Tap the save button to ensure the values persist after a power cycle. PT12 Manual 7/20/2021 Page 25 of 48 ...
Page 26: Current Mode
Operation 4.4.2 CURRENT MODE For each probe, the PT12 supports three independently selectable current modes, 1mA, 0.66mA, and 0.33mA. The approximate maximum measurable resistance for each current mode is listed in the table below: Current Mode Absolute Maximum Resistance (mA) (Ω) 1 128 0.66 192 0.33 384 The PT12 will attempt to get the most accurate reading possible with auto current mode enabled. It attempts to use the most suitable current depending on the probe’s resistance and the range of the reference resistors while preventing over/under range of the A/D converter. When in manual current mode, it is possible to over range the A/D converter if the probes exceed the resistances identified in the table above. This causes no harm to the system other than temporary errant readings. If the resistance of the probe is outside the range of the PT12 internal reference resistors, the probe readings may be less accurate. Tap the current mode drop‐down to switch between auto and manual current modes. If manual mode is selected, a secondary drop‐down appears allowing for selection of 1 mA, 0.66 mA, and 0.33 mA. Tap the save button to ensure the values persist after a power cycle. Current mode is saved to the channel only, regardless of the probe type (smart or basic). PT12 Manual 7/20/2021 ...
Page 27: Coefficient Mode
Operation 4.4.3 COEFFICIENT MODE The PT12 currently supports both Callendar‐Van Dusen (CVD) and ITS‐90 for calculating temperature. Each probe may be configured independently. If using a smart probe, the coefficients may be stored on the probe itself. Only one coefficient type may be used at a time to measure temperature, but both coefficient types may be stored on the probe (if a smart probe) or in the system (if a basic probe). CALLENDAR‐VAN DUSEN (CVD) To select CVD mode, tap the coefficient mode drop down and select CVD. In CVD mode, the PT12 calculates temperature from resistance by solving the following CVD equation for temperature (T): When T < 0 °C (or R < R ) �� ∗ 1 �� 100 �� [1] ...
Page 28: Its90
A 0.0039083 0.0037 < A < 0.0041 B ‐5.775E‐7 ‐4.0E‐7 > B > ‐7.5E‐7 Exponent of coefficient C should be no larger than E‐ 10. For example, coefficients of E‐10, E‐11, E‐12 and so C ‐4.183E‐12 on, are acceptable, but E‐9 would be outside of the acceptable range. Enter the probe’s specific values for R0, A, B, and C. There are two common forms of the CVD equation. The PT12 uses the A, B, C form. If the probe’s coefficients are , ,  (alpha, delta, beta), the following may be used to convert to the A, B, and C given in the other form as coefficients needed by the PT12. A = (100 + )/100 B = -/100^2 C = -/100^4 , ,  It is also possible to convert A, B, and C to (alpha, delta, beta) that may be required by other temperature measurement systems. ...
Page 29 660.323 A7, B7, C7 A=A7, B=B7, C=C7 8 0.01 419.527 A8, B8 A=A8, B=B8, C=0 9 0.01 231.928 A9, B9 A=A9, B=B9, C=0 10 0.01 156.5985 A10 A=A10, B=0, C=0 11 0.01 29.7646 A11 A=A11, B=0, C=0 To select ITS90 mode, tap the coefficient mode drop down and select ITS90. Depending on the sub range selected, the appropriate coefficients will appear. Select the desired subrange from the second drop down menu. PT12 Manual 7/20/2021 Page 29 of 48 ...
Page 30 Operation One of three different coefficient sets will be shown depending on the subrange selection. Enter the probe’s specific coefficients based on the sub range selection. Tap the save button to ensure the values persist after a power cycle. If using a smart probe, coefficients are stored on the probe. If using a basic probe, coefficients are stored on the PT12 channel. In the PT12, temperatures are determined per ITS90 in terms of the ratio (��) of the resistance of a probe (��) at a given temperature, and the resistance of that same probe at the triple point of water, R (where the temperature T is defined as 273.16K): PT12 Manual 7/20/2021 Page 30 of 48 ...
Page 31 �� is the temperature in Kelvin, �� is the reference resistance ratio, and �� and �� are constants given in the ITS‐90 standard. See the ITS‐90 standard for a more complete definition, as well as the full table of constants for �� , �� , �� , and �� . No probe is ideal of course. Each exhibit small deviations that make their temperature vs. resistance characteristics unique. To account for this, ITS‐90 provides “deviation functions” for various temperature subranges, each with their own equation and probe specific coefficients. These deviation functions provide unique probe correction to the reference resistor ratio equation. The deviation functions utilized by the PT12 are listed below. ITS‐90 mode below triple point of water using A4, B4: �� 4 �� 4 �� 1 ∗ ln �� ...
Page 32: Probe Configuration Management
Given W and the coefficients A, B, C, A4, B4, A5, B5 and the corresponding deviation equation, �� is calculated for the probe’s unique non‐idealities for the specific sub range of interest. �� is then used with the corresponding inverse reference equation (equation [4] or [5] depending on value of �� ) to compute the actual temperature in Kelvin. 4.4.4 PROBE CONFIGURATION MANAGEMENT Each probe’s configuration may be imported, exported, defaulted, and saved. The averaging and current mode selection are always saved to the channel. If using a basic probe, the coefficients will also be saved to the channel. However, if using a smart probe, the coefficients will be saved to the memory chip within the probe. Import Export Default Save Import Configuration: Imports a previously stored configuration file from the system to a probe or channel. This is especially useful when moving a basic probe from one channel to another. Click the import button and then select the desired configuration file. PT12 Manual 7/20/2021 Page 32 of 48 ...
Page 33 Operation Imports the selected file Deletes the selected file Cancel/Close window Export: Export a probe’s current configuration to a file. This is useful when moving a basic probe from one channel to another. On export, the keyboard will display for entry of a filename. The default filename is the channel appended by the current date. Default: Return a probe’s configuration to default. This sets the coefficient mode to CVD with default coefficients. See section 4.4.3.1 Callendar‐Van Dusen (CVD) for more information on defaults. Save: Save the probe’s configuration. For a smart probe, the configuration is stored within the probe itself. For a basic probe, the configuration is stored on the channel. Averaging and current mode are stored only on the channel, never on a smart probe. PT12 Manual 7/20/2021 Page 33 of 48 ...
Page 34: File Manager
Note: Do not unplug probes while saving is in progress. Unplugging a probe during a save could corrupt the memory chip. FILE MANAGER The file manager page is used for copying logs to a USB drive, deleting old logs from the system, and setting the preferred logging location. 4.5.1 COPYING LOG FILES TO USB DRIVE Attach a USB flash drive (must be pre‐formatted to FAT‐32, EXFAT, NTFS, or EXT4) and select which logs you would like to copy to your USB drive. External USB connection status Export selected log(s) to USB Select all Delete selected log(s) 4.5.2 DELETING LOG FILES Delete old log files from this menu by selecting the unwanted files and tapping the delete button: PT12 Manual 7/20/2021 Page 34 of 48 ...
Page 35: Set Preferred Logging Location
Operation 4.5.3 SET PREFERRED LOGGING LOCATION To log directly to a USB drive, ensure a USD drive is attached, then select USB from the ‘logging location’ drop down menu. This will create a new log file on the attached USB drive and start logging directly to that drive. The files do not appear on the system, only on the USB drive. If the USB drive is removed, logging will automatically revert back to the local system. To log to the PT12 local internal memory, select ‘Local’ from the logging location drop down menu. Files will not log to the USB drive. PT12 Manual 7/20/2021 Page 35 of 48 ...
Page 36: System Info
Logging active: To start a new log file, toggle this off then on. Leave it off to stop logging. Style: Dark or Light mode theming. After selection, the change requires several seconds to complete, during which time the screen remains locked. Graph data resolution: The number of digits displayed when clicking on plotted points. Graph statistics resolution: The number of digits to display in the graph statistics. System unit control: Another location to change system units. Serial communication and logged data always occur in °C and ohms regardless of the units selected for display. Time zone: UTC time zone set for log file or graph. If the time zone is changed while logging, the graph will update properly but the log file will have a time discontinuity forwards or backwards depending on which time zone is selected. After changing time zones, it is recommended to toggle logging off and on to create a new log file. PT12 Manual 7/20/2021 Page 36 of 48 ...
Page 37: Serial Communications
Serial Communications SERIAL COMMUNICATIONS The PT12 may be connected to a PC for continuous communication. All communication is managed in a polled format. The PT12 never sends information without being queried. SERIAL CONNECTIONS USB to Serial RS‐232 5.1.1 ELECTRICAL WIRING TO THE RS‐232 PORTS Connect the RS‐232/USB converter to the PC’s USB port, then connect the other end to the PT12 using a standard RS‐232 9‐pin extender cable. The extender cable has a male connector on one end and a female connector on the other end. It is wired straight through with pins 1 through 9 on one end wired to pins 1 through 9 on the other end. The PT12 ignores the DSR and CTS handshaking signals. While there is no harm in connecting all 9 pins, the PT12 only requires connection of three of the pins (TxD, RxD, Gnd). For your reference, the complete connector pin‐out is listed in the following table. Note that those signals identified by * are required, while the others are completely optional. RS232 PIN OUT 5 3 2 ...
Page 38: Serial Configuration
Serial Communications Signal PT12 (9pin) Direction Computer (9pin) 1 1  *TxD 2 2  *RxD 3 3 DSR  4 4 *GND -- 5 5 DTR  6 6  CTS 7 7 RTS  8 ...
Page 39: Protocol
Serial Communications PROTOCOL 5.2.1 COMMUNICATION SEQUENCE AND TERMINATION CHARACTERS All commands sent to the PT12 must be terminated with either a carriage return or a carriage return linefeed . Both combination and terminators are identical in action as the PT12 simply ignores the character. For those writing communication programs to communicate with the PT12, note that and are represented by the following values: Symbol Decimal Hex 13 0D 13,10 0D 0A When using a terminal emulator such as Hyper‐terminal or Putty, note that pressing the Enter key is equivalent to sending R. Regardless of the command sent, the PT12 will reply with a carriage return linefeed terminator at the end of ...
Page 40: Command List
Serial Communications COMMAND LIST 5.3.1 SYSTEM LEVEL COMMANDS System level commands have nothing prepended. A few examples of system commands are: (sent by the computer to the PT12 to query the system current mode) (sent by the T1 back to the computer) (sent by the computer to the PT12) PT12 (sent by the T1 back to the computer) Command Typical Response (Read Command) or Input Notes Values (Write Command) ID? PT12 IDN? PT12 SN? T21X123 10‐digit Alpha Numeric SN Read/set global I? ...
Page 41: Channel Commands
Serial Communications 5.3.2 CHANNEL COMMANDS Each channel command can be run to query for temperature in °C. Each channel command has associated sub commands that pertain to that individual channel or probe’s configuration. The channel commands are T1 through T12. For example: (sent by the computer to the PT12 to query probe 3 temp) 24.1234 (sent by the PT12 back to the computer temp in °C) Command Typical Response Notes (Read Command) See sub command list below. T1[.][?] 25.123 See sub command list below. T2[.][?] 25.123 See sub command list below. T3[.][?] 25.123 See sub command list below. T4[.][?] 25.123 See sub command list below. ...
Page 42 8 Number of measurements to include in average of value. Typical range 0‐ T1.AVGCOUNT= 100 SAVE=RHS to save the config. RHS T1.SAVE=RHS N/A must be uppercase. T1.DEFAULT=RHS N/A DEFAULT=RHS to set the channel config to default. Does not save without running a save command. RHS must be uppercase. Note: All of the channel commands for T2‐T12 are identical to the commands above. Just replace T1 with T2‐T12 for the desired channel. PT12 Manual 7/20/2021 Page 42 of 48 ...
Page 43: Probe Commands
Serial Communications 5.3.3 PROBE COMMANDS Each probe command must be proceeded by the channel and probe # (i.e., T1). The probe commands are used mainly for setting coefficients. Note: None of the probe commands will persist without calling the SAVE command(above). Some examples of a probe command are: T1. PROBE.CVDR0? (sent by the computer to the PT12) 100.0 (sent by the PT12 back to the computer) T1.PROBE.CVDR0=99.99 (sent by the computer to the PT12) ...
Page 44 ‐0.001 Read the probe’s ITS90 A4 Coefficient T1.PROBE.A4= ‐1≤A4≤1 T1.PROBE.B4? ‐0.001 Read the probe’s ITS90 B4 Coefficient T1.PROBE.B4= ‐1≤B4≤1 T1.PROBE.A5? ‐0.001 Read the probe’s ITS90 A5 Coefficient T1.PROBE.A5= ‐1≤A5≤1 T1.PROBE.B5? ‐0.001 Read the probe’s ITS90 B5 Coefficient T1.PROBE.B5= ‐1≤B5≤1 Note: All of the channel commands for T2‐T12 are identical to the commands above. Just replace T1 with T2‐T12 for the desired channel. PT12 Manual 7/20/2021 Page 44 of 48 ...
Page 45: Calibration
Calibration CALIBRATION Contact RH Systems for calibration options. Contact information is located at the end of the table of contents. PT12 Manual 7/20/2021 Page 45 of 48 ...
Page 46: Uncertainty
Uncertainty UNCERTAINTY The PT12 is a versatile 12 probe PRT temperature measurement device accurate to within ± 0.0003 Ω over a customizable range. In a Characterization with a PT12 optimized for 100 Ω PRTs, the maximum observed uncertainty was within ± 0.0003 Ω for values under 180 Ω. The PT12 was characterized using calibrated precision resistors, and uncertainty was calculated for each channel using the following equation: Δ σ Where is the deviation of the average indicated value from the characterized reference value applied, is the standard deviation of the indicated values, and R is the uncertainty of the reference resistances applied during the characterization. The following table contains the mean and maximum channel uncertainties observed: Resistance (Ω) Maximum Channel Uncertainty (Ω) Average Channel Uncertainty (Ω) 5.00015752 0.000316876 0.0002589 25.001911 0.000363353 0.0002798 60.0049527 0.000189909 0.0001655 100.005241 ...
Page 47: Specifications
Specifications SPECIFICATIONS Specifications: Thermometer PT12 Measurement Ranges Temperature ‐200‐660°C Resistance 1‐380 Ω Measurement Performance For the range of ‐200...+250 °C Resolution 0.1 mK Accuracy ≤ ± 2 mK @ 23 °C (95% confidence level, 1 year) Temperature coefficient 0.1 mK / °C Standard Features Available inputs 12 Channels Input type Pt‐100 and Pt‐25 Platinum Resistance Thermometer (PRT), 4‐wire, Supports Smart 4‐wire PRTs Supported coefficients ITS‐90, Callendar‐Van Dusen Excitation current 0.33, 0.66 and 1mA resistance, DC polarity reversing ...
Page 48: Document History
PT12 Manual 7/20/2021 Page 48 of 48 ...