CONTENTS PAGE 1. INTRODUCTION 1 Full description of the DP97 Front Panel information at a glance 2. INSTALLATION 3 Supply Connection Input connections – Sensors 3. OPERATION i) ii) iii) iv) v) 4 To read sensor temperature directly To read differential temperature Matching DP97 to calibrated sensors Error indications ¾ wire recognition 4. INSTRUMENT RE-CALIBRATION 6 5. ANALOGUE (RE-TRANSMISSION) OUTPUT 8 Connection and Operation 6.
1. INTRODUCTION A high precision portable thermometer for metrology and other exacting laboratory applications, the DP97 is a proven instrument used world wide as a laboratory and site standard in pharmaceuticals, medical, food, environmental testing, R & D, and general industrial applications. It is particularly suitable as the reference standard for temperature calibration baths.
Front Panel Information at a Glance: when you switch on To obtain a reading from a temperature sensor, select channel A or B (1) and select the required units (2). The appropriate indicator LED indicates the selected channel and units. For version 2.1, the A and/or B LED indicators, according to the channel selected, cycle between a steady on state and a brief off state (occulting) when corrections are stored and applied to measurements (not applicable to version 1.4).
2. INSTALLATION Back Panel General a) b) The standard version is for bench-top use. Retractable legs can be extended to provide a convenient viewing angle. The optional version permits the installation of the DP97 into a suitable panel cut out. Supply Connection Primary power is provided by the internal, rechargeable sealed lead-acid battery which provides up to 12 hours operation from a full charge.
3. OPERATION Ensure that the instrument is connected to a suitable supply or has charged batteries and that the required input connections are made. Switch “on” using the rear mounted rocker switch. The display will show “Pr 2.1” or “Pr 1.4” the programme designation. There is a short delay while internal checks are carried out, then the input A value will be displayed. i) To read sensor temperature directly a) PRT input A is automatically selected at switch-on.
iii) Matching DP97 to Calibrated Sensors It is possible to automatically match the DP97 to a Pt100 sensor with up to 10 dedicated calibration values. Such values, published in an associated certificate indicate true Ω versus °C values corresponding to accurately known reference temperatures. Up to 10 sets of values per sensor can be fed into the instrument via the RS232 interface using the associated software supplied with each version 2.1 instrument as standard.
If using a shorter leadout from the probe or thicker gauge cable, please ensure that the DP97 is in the correct wire recognition mode. This can be checked by pressing the SPAN s button ONCE. Two numbers will be displayed e.g. 3-4. The first digit being the X parameter (e.g.3) and the second digit being the Y parameter (e.g.4). These displayed numbers will only be displayed momentarily. Caution, pressing the SPAN s button more than once or holding it down continuously will alter the X-Y setting.
Page 6 The calibration kit option (two precision resistors) is required to perform re-calibration. No additional instruments are required since the DP97 self-calibrates as follows: Caution: Do not proceed unless specified resistors are available. Failure to do so may invalidate the warranty. a) With the supply disconnected, remove the instrument case cover by removing the two screws on the rear panel and sliding the cover off the rear of the instrument.
Page 7 Switch off the Instrument 1) Remove the jumper lead JP1. This is VITAL. Should the instrument be switched on with JP1 In position, the calibration is lost. 2) Replace the instrument cover. The instrument is now ready for normal use. The central processor is software driven and no other adjustments or modifications should be attempted. If it is necessary for the supplier to re-calibrate an instrument in consequences of unauthorised persons so doing, a charge may be made accordingly 5.
Page 8 6. RS232 COMMUNICATIONS General Remote control will be seized by sending an RS232 character, and relinquished by sending the LOCAL command. While in remote control the front panel buttons will be locked out (inoperative) and the right hand decimal point will indicate remote operation (local lock-out). RS232 parameters will be a fixed baud ate and word length. 9600 Baud, 8 Data, No parity, 1 stop bit. Remote control of calibration has not been included. (Refer to section 4).
Page 9 Command set: Display parameters: UNITS UNITS UNITS UNITS INPUT INPUT INPUT OHMS C K F A B A-B Analogue parameters: SPAN Value in Ohms ZERO Value in Ohms Measurement: MEASURE Return to Local: LOCAL Output Protocol Replies will depend on the command implemented, and will be numeric or – with commas and spaces as delimiters. All replies will be terminated by CR and LF. The first number will be an error code.
Page 10 For digital probe matching within the instrument (version 2.1 only) additional commands are used as follows: CORRECTIONS A B AB OFF (turns OFF B corrections) Turns A on (turns OFF A corrections) Turns B on (turns ON BOTH A & B corrections) (turns OFF BOTH A & B corrections) Whatever is set by this command is retained during power-down.
Note: Use of the DP97 “CORRECTIONS PC SOFTWARE” supplied with the instrument facilitate the correction procedure by means of a much simplified, user-friendly approach described below. 7.
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b) Using the software From MAIN MENU:To input calibration values into the DP97 (up to 10 may be used per channel): º Click EDIT to obtain EDIT corrections menu. º Enter values against #01 through #10 but note that i) ii) iii) º º º º All 10 need not be entered When returning to main menu the Ù values are sorted into ascending order. If the corresponding °C values are not in ascending order, the status box will show Error. All values must be entered with up to three decimal places e.g. 0.001, 10.001 etc.
Stored values can be viewed at any time as follows: º From Main Menu, click CHANNEL to select channels A OR B º Click READ Stored values can be changed at any time by repeating input procedure. Stored Values can be cleared from the DP97 at any time as follows: º From Main Menu, click CHANNEL A <-> B º Click DISABLE º Click PRINT in load/save/print menu to print out corrections. To exit programme and return to DOS, click EXIT on Main Menu.
General Range/Sensor type Pt100 to IEC 751 (ITS 90 refers). –199.99 to 849.99°C.Ro = 100Ω. Two input channels, each 3 or 4 wire connection with automatic recognition (with manual overrride). Overall Instrument Accuracy (4 wire) ±0.02°C ± 1 digit for range -200°C to +500°C. ±0.005% reading ± 1 digit for range 500°C to 850°C. Overall System Better than ±0.04°C with TM-l250 precision probe accuracy (4 wire) from -50°C to +250°C with 5 point NAMAS calibration. Linearisation Conformity ±0.01°C.
Charger requirement 10 – 11.5V d.c. 1A. Power Consumption 10W nominal. Max 20W when battery is charging. Series Mode Rejection 60dB @ 50Hz (50mV rms applied). Common Mode Rejection Ambient Temperature Range 30V rms applied between input and earth produces no measurable effect. 0-50°C non-condensing. Ensure stable temperature range for best accuracy. Allow adequate warm-up time if moved from region of low ambient temperature prior to use. EMC Compliance Meets EMC regulations.
Communications RS232 (standard) PC Software (standard) Analogue Output (standard) Remote control and measure, Isolated, 9600 Baud, 8 data, no parity, 1 stop bit. PC software running in MS DOS allows programming (standard) of custom calibration and preview of set values from a PC. Also provides a print facility and storage of sets of correction values. Analogue 0 to 1 Volt d.c. between programmable (standard) lower case and upper set limits representing channel A, B or A-B. Accuracy 0.5% of reading.
OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a period of 13 months from date of purchase. OMEGA’s WARRANTY adds an additional one (1) month grace period to the normal one (1) year product warranty to cover handling and shipping time. This ensures that OMEGA’s customers receive maximum coverage on each product. If the unit malfunctions, it must be returned to the factory for evaluation.
USA: ISO 9001 Certified One Omega Drive, P.O. Box 4047 Stamford CT 06907-0047 TEL: (203) 359-1660 FAX: (203) 359-7700 e-mail: info@omega.com Canada: 976 Bergar Laval (Quebec) H7L5A1 TEL: (514) 856-6928 e-mail: info@omega.
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