Group3 DTM-133 User Manual
  1. Manuals
  2. Brands
  3. Group3 Manuals
  4. Measuring Instruments
  5. DTM-133
  6. User manual

Group3 DTM-133 User Manual

Digital teslameter
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
DTM-133
DIGITAL TESLAMETER
with IEEE-488 GPIB Communication
V1.0
USER'S MANUAL
01 April 2010
Group3 Technology Limited
2 Charann Place, Avondale, Auckland 1026
P.O. Box 71-111, Rosebank, Auckland 1348, New Zealand.
Phone: +64 9 828 3358
email:
sales@group3technology.com
web:
www.group3technology.com
Fax: +64 9 828 3357

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the DTM-133 and is the answer not in the manual?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for Group3 DTM-133

Summary of Contents for Group3 DTM-133

  • Page 1 DIGITAL TESLAMETER with IEEE-488 GPIB Communication V1.0 USER’S MANUAL 01 April 2010 Group3 Technology Limited 2 Charann Place, Avondale, Auckland 1026 P.O. Box 71-111, Rosebank, Auckland 1348, New Zealand. Phone: +64 9 828 3358 Fax: +64 9 828 3357 email: sales@group3technology.com...
  • Page 2 Thank you for purchasing and using a Group3 digital teslameter. We hope you will join the many hundreds of users worldwide who are enthusiastic about our products. Group3 has been designing and building magnetic field measuring equipment since 1983. We are constantly upgrading our products and support documentation.

  • Page 3: Table Of Contents

    Table 5 String Terminator Switch Settings Table 6 IEEE-488 Command Codes Table 7 DTM-133-_G IEEE-4888 Command Codes 5-12 Table 8 DTM-133-_G Commands - alphabetic listing 5-13 Table 9 DTM-133-_G Commands - listing by function 5-16 DTM-133 User’s Manual Contents -1...
  • Page 4 Contents -2 DTM-133 User’s Manual...

  • Page 5: General Description

    The DTM-133 Digital Teslameter offers accurate measurement of magnetic flux density, with direct digital readout in tesla or gauss. The instruments are light and compact, and the probes are easy to use. The DTM-133 has been engineered to withstand the severe electrical interference produced by high voltage discharge.
  • Page 6 With the serial option, a single teslameter may be connected to standard RS-232C equipment, or up to 31 units may be interconnected on the Group3 Communication Loop (G3CL) and driven from computer or terminal. Fiber optic ports duplicate functions of RS-232C signals, for electrical noise immunity and voltage isolation. Fiber optic links may be up to 60 meters in length using Hewlett- Packard HFBR-3500 series improved fiber optic cables.
  • Page 7 2. SPECIFICATIONS OF A DTM-133 SYSTEM Measurements Field magnetic field density in tesla or gauss ranges tesla full-scale, kilogauss full- scale, with polarity indication and selectable auto ranging maximum calibrated field +2.2 tesla +22 kilogauss Resolution 1 in 12,000 of bipolar span with digital filtering on...
  • Page 8 0.5 millitesla with multi-range probe. Temperature range 0 to 50°C operating, absolute maximum temperature of probe 60°C Instrument weight 1.2 kg, shipping weight: 2.5 kg Probes standard sensitivity transverse types: LPT-130, MPT-132 high sensitivity transverse types: LPT-230, MPT-230 DTM-133 User’s Manual...
  • Page 9 Digital interfacing serial option: RS-232C and fiber optic; parallel option: IEEE-488 General Purpose Interface Bus System orientation Group3 Communication Loop (G3CL) using serial ports, simple loop for 31 devices no multiplexer required: GPIB with IEEE-488 option. Digital data format ASCII input commands and output responses Commands requests for field value;...
  • Page 10 0.03, 0.06, 0.12, 0.3 tesla full scale for high sensitivity probes support all LPT and MPT series probes, plugpack supplied except for option -L. DTM-133 (recommended probes are LPT-130, LPT-230, MPT-132, MPT-230) Options Bench style instrument with display: add suffix -D...

  • Page 11: Setting Up

    3.2 INSTALLING THE PANEL MOUNT OPTION Model DTM-133-P is supplied fitted with a special front bezel which has threaded studs to allow panel mounting. A panel mount support bracket (part 17000058) is included to help support the teslameter. Group3 can supply 19-inch wide, 2U (3.5") high rack panels to hold one, two, or three teslameters (parts 17000025, 17000026, and 17000027,...

  • Page 12: Connecting The Hall Probe

    The DTM-133 must be used with a Group3 Hall probe. Probe models LPT-130, LPT- 230, MPT-132, or MPT-230 are the most suitable for use with the DTM-133. The probe may be one supplied with your teslameter, or it may have been obtained separately.

  • Page 13: Connecting The Power Source

    For extra immunity to damage and operational disturbance caused by serious high voltage sparking near the teslameter, the use of the Group3 model PS12D7 off-line switch-mode power supply and the Group3 ferrite kit part no. 11000036 is recommended. These accessories will greatly reduce the amount of electrical transient energy entering the teslameter.
  • Page 14 The power input must be connected as shown to include the thermal fuse in the circuit correctly. If a fault causes transformer overheating and subsequently the fuse opens, the transformer must be replaced with the genuine Group3 part. Fig. 2. Power Input Connections of the -L option If desired, the wiring may be protected by installing an external fuse in the ac power feed.

  • Page 15: Internal Dip Switches

    The cable shield is added to the case shield and extends protection from electrical interference almost up to the probe head. DTM-133 User’s Manual...

  • Page 16: Installation Techniques For Electrically Noisy Environments

    3.8 INSTALLATION TECHNIQUES FOR ELECTRICALLY NOISY ENVIRONMENTS The DTM-133 is a precision electronic measuring device. Because of the nature of the measurements, it is asked to do, it is frequently exposed to conditions that are considerably worse than are normally encountered by precision instruments.
  • Page 17 The fiber optic cables used with the DTM-133 are economical and convenient to use - simpler in fact than wiring. To interface the fiber optic cables to your computer or other data acquisition system, use a Group3 model FTR fiber optic adaptor.
  • Page 18 Group3 can supply an alternative power supply to be used instead of the usual plug pack. The alternative power supply is model PS12D7. It is a universal voltage (85 - 270V 50/60Hz) input, 12Vdc 7W output unit with excellent input-output isolation for noise and transients.

  • Page 19: Operating Instructions

    4. OPERATING INSTRUCTIONS 4.1 ZEROING The DTM-133 digital teslameter has a very stable zero field reading. Nevertheless, it is good practice to zero the instrument on all ranges immediately prior to making critical field measurements. The zeroing process takes out residual zero errors in the Hall probe and the instrument's preamplifier "front-end".

  • Page 20: Installing The Probe

    4.2 INSTALLING THE PROBE Group3 Hall probes are built to be as robust as possible for a small, precision device. However, it is most important that certain precautions be taken when handling and installing probes so that they are not damaged or destroyed, and to preserve their accurate calibration.

  • Page 21: Reading The Field Value

    The field value is read directly off the display. A negative sign indicates that the field direction is opposite to that described in section 4.2. The DTM-133 has autoranging capability and powers up in this mode. Autoranging can be enabled or disabled using the front panel MODE key. See section 4.4 below.

  • Page 22: Display Modes, Using Front Panel Keys

    The RANGE key is also used to reload system defaults, as follows: remove power from the teslameter press and hold the RANGE key apply power to the teslameter after the display lights, release the key the display message rESEt confirms defaults reloaded. DTM-133 User’s Manual...
  • Page 23 The message GrouP 3 appears in the display for 2 seconds when the teslameter is first powered. This message is followed by SErlAL if the serial communications option is fitted, or GPIb if the GPIB IEEE-488 option is fitted. DTM-133 User's Manual...
  • Page 24 If the overflow message appears on a DTM-133, it can usually be cleared by reloading defaults (see section 4.4.1). Otherwise, please contact the supplier of the teslameter.

  • Page 25: Digital Filtering

    Field measurements are made at a fixed rate of 30 per second, so P = 0.033. With the default value of J - 8, the filter time constant is 0.25 seconds. This gives a cut-off frequency in the displayed field reading of 0.64Hz. _____________________________________________________________________________________________________ DTM-133 User's Manual...

  • Page 27: Ieee-488 Bus Connection

    Ground wire of twisted pair with NDAC GND 9 Ground wire of twisted pair with IFC GND 10 Ground wire of twisted pair with SRQ GND 11 Ground wire of twisted pair with ATN teslameter logic ground Table 3. IEEE-488 Connector Pin Assignments DTM-133 User's Manual...
  • Page 28 Fig.4. IEEE-488 Standard Connector. Fig.5. Location of IEEE-488 Board Switches. DTM-133 User’s Manual...

  • Page 29: Ieee-488 Board Switch Settings

    5.2 IEEE-488 BOARD SWITCH SETTINGS The IEEE-488 board in the teslameter is provided with two sets of DIP switches, allowing the user to set up teslameter operation and communications according to system requirements. To obtain access to the switches, remove the bottom cover by loosening the single central screw. Refer to Fig. 5. page 5-2 for switch locations. Switch functions are as follows: 8-way DIP switch - sets device address on IEEE-408.
  • Page 30 DTM-133 User's Manual...

  • Page 31: Using The Ieee-488 Gpib Interface

    Up to 15 instruments may be connected on the bus at any one time, and they are considered to be listeners (able to receive data), talkers (able to transmit data) or controllers (able to control and configure the bus). DTM-133 User’s Manual...
  • Page 32 Fig. 6. A Typical IEEE-488 System DTM-133 User's Manual...
  • Page 33 When the controller wishes to designate the talker and listeners for the next sequence of bus transmissions, it asserts the bus management line called Attention (ATN) and then sends the appropriate talker and listener address commands to assign the desired talker and listener(s) required for the next transaction. The controller then releases the DTM-133 User’s Manual...
  • Page 34 When the controller wants to make a device into a talker, it places the device’s talk address command on the bus. This command is given by talk address command = decimal 64 + device address. DTM-133 User's Manual...
  • Page 35 To cause all listeners to stop listening, the controller sends the Unlisten comm and, decimal 63 (hex 3F ASCII ?). To stop the talker being a talker, the Untalk command is sent. i.e. decimal 95 (hex 5F, ASCII_). DTM-133 User’s Manual...
  • Page 36 2) ascertain the action required (serial poll) 3) execute the required action 4) re-enable interrupts 5) return to the task in hand before being interrupted. The SRQ line is released by the device when the aerial poll is performed. DTM-133 User's Manual...
  • Page 37 There are two forms of this command; the Device Clear command (decimal 20) causes all devices on the bus to be cleared. whereas the Selected Device Clear command (decimal 4) clears only devices selected to listen. 5-10 DTM-133 User’s Manual...
  • Page 38 G IEEE-488 Capability Th e IEEE -488 Standard defines ten interface functions. some with as m any as 28 allowable subsets. The DTM-133- G teslameters support the interface functions as listed below. See also Appendix C of the IEEE-488-1978 Standard.
  • Page 39 Group3 COM-488 IEEE-488 to Serial Adaptor which converts the bus traffic to serial data format.
  • Page 40 If no number is entered where one is expected, zero will be entered automatically. If an error message is returned, the command must be re-entered. The default values apply after system reset command CTRL X. For switch-selectable defaults, see Table 4 TABLE 8. DTM-133- G COMMANDS - ALPHABETIC LISTING command description B<text><cr>...
  • Page 41 CTRL X Restarts operating software as if DTM had been freshly powered up. Load system defaults - all default values & modes reinstated. The message RESET is transmitted. End of Table 8 5-14 DTM-133 User's Manual...
  • Page 42 The status bit in the serial poll response will always be asserted if there is data available to be read. The SRQ bit is reset to the false state after the serial poll and is only re- enabled when data is read from the teslameter. 5-15 DTM-133 User’s Manual...
  • Page 43 TABLE 9. DTM-133- G COMMANDS - LISTING BY FUNCTION COMMUNICATIONS Address – all following commands are acted on only by the unit of address n (n=0 through 30) as set on internal switches. Sampling interval - enters interval between output field values.
  • Page 44 General function Triggered - field is measured only on V command GC returns to normal mode. Triggers field measurement after triggered mode selected by GV Inspect General function - returns C for continuous. V for triggered 5-17 DTM-133 User’s Manual...
  • Page 45 POSITIVE NUMBER REQUIRED indicates erroneous entry of minus sign. FIXED RANGE PROBE and AUTORANGING indicate an illegal attempt to change range. The messages NOPROBE, OVERFLOW, and OVERRANGE duplicate the functions of these messages on the DTM display. 5-18 DTM-133 User's Manual...

  • Page 46: Triggered Operation

    The effective time-constant will depend on the timing of the trigger commands. If the field values obtained on triggering are required to reflect only the field at the time of triggering and not contain any history, then filtering should be turned OFF. 5-19 DTM-133 User’s Manual...
  • Page 47 After a range change — manual or autoranging — it takes the circuitry and calculation path some time to settle with the new values. Disregard any readings for 2 seconds following a range change. If continuous readings are required, it is suggested that autoranging be disabled. ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 5-20 DTM-133 User's Manual...
  • Page 48 GROUP3 TECHNOLOGY LTD LIMITED WARRANTY Group3 Technology Ltd. (hereinafter called the Company) warrants instruments and other products of its manufacture to be free from defects in materials and workmanship that adversely affect the product’s normal functioning under normal use and service for a period of one year from the date of shipment to the purchaser.
  • Page 49 DISTRIBUTORS & REPRESENTATIVES Australia, New Zealand and Rest of the World Germany Schaefer Technologies GmbH Group3 Technology Ltd. Robert-Bosch-Straße 31, 63225 Langen 2 Charann Place Germany Avondale Auckland New Zealand Ph: +49 6103 30098 0 Ph: +64 9 828 3358...

Table of Contents