datron 1081 manual
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datron 1081 manualDid you miss your activation email ? It gives an Error 7 when the self-test is run. I'm hoping the error is an AC self-test failure, like it is on lower specced Datron meters. While I'm waiting for the unit to arrive, I'm looking to get my hands on electronic copies of the users, calibration, and service manuals. I've checked on KOBB, and Kurt's archives of manuals, and I've been crawling through Google results, but haven't had any luck so far. Do any of you have scans of these documents you'd be willing to share? Thanks! I suppose that the relays could be tested on the relay pins, but I usually leave the insulation attached unless I have to burnish a relay. I don't have the device yet, it should be here sometime this week. From careful inspection of the photos in the listing, it appears the Guard switch was switched to remote, so it seems you may have upgraded my Datron 1081 with a damaged case and a self-test error to a Datron 1081 with a damaged case. Photos also show that the options listed on the back panel are 10, 20, 40, 50, 70, 90 I am going to give it a good looking over when it arrives, though I lack any good LCR or ESR meters. Even though someone may have already changed it, it can be changed to operate with 115 Vac line power input (instructions on REAR PCB layout in the manual that you posted a link to). The service manual is available, but I've not found the user's manual Cheers, DC1MC. From the photos, it looked like the shipping damage was confined to a broken “ear” on the front of the case, and misalignment of the front panel.I couldn’t find an operators manual for the 1081, but I hoped the 1071 manual I found was correct that the selftest error was with the AC measurement circuitry. I’m mainly interested in DC, so I wasn’t too concerned. At this point, I was back home, with the ability to browse eBay without the limits of a phone. I should have taken advantage of this to investigate past listing a little more thoroughly.http://static.yuka.ro/img/ezrun-60a-esc-manual.xml
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If I had I would have realized that some of the higher sales prices weren’t actually sales, they were expired listings that eBay wasn’t filtering properly. I didn’t though, instead I accepted the offer. It arrived last Friday, packed well in a Cisco router box with reused foam endpieces and packing peanuts for extra protection. It was in the physical condition I expected; the case damage was limited to an extremity, and the main enclosure was sound. I opened it up for inspection and to deal with the misaligned front panel. The sticker holds a smoked plastic protective lens over the display. The sticker was loose at a few spots, including the protective lens, which allowed dust and exposure to further weaken the adhesive. I decided to remove it, clean it up, and reattach it. I ended up peeling the outer layer and printed layers of the sticker off its backing. Some adhesive remained on on the printed surface of the label, and the backing remained stuck firmly to the metal plate. I used a plastic scraper to remove most of the backing, but getting the rest off required a razor blade, elbow grease, and solvents (“Goo Gone” worked best). I used isopropyl alcohol to clean the remaining adhesive off the back of the printed sheet. Unfortunately I think the process of peeling off the label led to some of the printed brown background along the left side of the lower edge crazing and flaking off. I considered trying to apply a new background of spray paint, but decided the risk of causing further damage wasn’t worthwhile. I smeared a thin layer all over the back of the sticker, and around the edge of the smoked lens before lining everything up and sticking it back down, smoothing it out and wiping off any ooze. I weighted the area over the lens and let it cure for a few hours before reattaching it. Repair would be challenging. Either the battery hadn’t been changed, or whoever did so was too lazy to update the label.http://www.asclyziarskyklub.sk/userfiles/ezr-regulator-manual.xml Inside I found the truth, the battery had a datecode of 1984, like most of the other components. Fortunately it still had a voltage of 3.7v, but I’ll be changing it soon. Together, they make up the heart of the voltage reference. They are each numbered with a unique serial number because they were carefully aged for months (or years), then characterized for noise, stability, voltage, and the current at which they have flat temperature sensitivity. My understanding is that the four Zener are connected as two parallel series of two. The use of hand-selected temperature compensated Zener was a common practice in a variety of precision instruments at one time, even so, the use of multiple TC Zeners was unusual, as is the stability they obtained. Also by the mid-1980s, when this device was made, use of temperature stabilized burried-Zener voltage references, like the LM199 (introduced in 1976) was commonplace. Most of the components on the AC RMS converter board, and most of the other boards, have date codes no later than mid-1984, but the Fairchild opamp in the hermetically sealed package in the photo above is dated from 1987. The GPIB board seems to date from 1985, and there are some socketed ICs on another board that have 1986 date codes, while other chips on the board are from 1982 or 1983. On the EEVBlog forum, “dacman” suggested that self-test error could simply be the result of running the tests with the “guard” switch was set to remote. I could see from the photos on the listing that it was, indeed, set to remote, and it still was when I received it, so I set it to local guard and ran the self tests. Everything passed! The EDC hasn’t been calibrated in years, though from my tests, it is accurate to within the combined 1year tolerances of both it and all my 6.5 digit DMMs. The readings are stable over the short term. Sometimes the Datron has reported a wider range than the Keithley, sometimes a narrower range. I’ll need to get logging working over GPIB soon so I can can look more closely at the trends. After the initial readings seemed good, I left it for a while and checked it while I worked. About 15-30 minutes in, I looked over, and it was reporting values of 110v or more, and they were changing quickly. I haven’t been using the EDC much in its 100v range, so I breifly considered the possibility that it was at fault, but a quick look at the Keithley 2700 measuring the same source showed that the voltage was still stable at 100v. I cut the EDCs output and after about 30s, the Datron cleared the overload message and started giving readings again. I applied an input again (I can’t remember if it was 10v or 100v), and it again gave plausible readings. I left it for a while and continued checking it, and after a while, it was again reporting an overload. This time cutting the EDCs output didn’t clear the overload message, and I ended up power cycling it. I have had it with a 100v input for the last 18 hours or so though, and its been solid. I’m beginning to suspect that the problem may have been the result of user error. At some point, I think I’d used a function that “zeros” the meter. I thought this worked like the relative measurement option on my Keithleys, which can give readings relative to any voltage. The Datron 1081’s feature is different. The zero-point is supposed to be set with the inputs shorted, and the value is stored and used until the next time the meter is zeroed. If it is more than a small portion of the full range (1 or so), it will give a overange error. I’m wondering if perhaps the zero-point that I or someone else previously set was near the limit, and perhaps some internal auto-correction ended up pushing things over the limit. This is just a stupid wild ass guess though. All I can be sure of is that since setting the zero point for all the ranges with the input shorted, I haven’t had this happen again. When I checked it the next morning, I suspected that the display had frozen because the last digit didn’t change once. I pushed a button to change the value displayed, and was treated to the above, after a minute or two, it seemed to reset itself and resume operation. The first button I hit produced a similar result to the previous day. I tried hitting another button (I don’t remember which) and the rest of the display segments and all the indicator LEDs on the buttons lit up too. This time, it didn’t reset itself, at least not before I got tired of waiting. A few days ago though, I decided to investigate a hunch. I thought that that when I saw this problem behavior previously, I may have left the unit displaying the delta between minimum and maximum values. So, I again left it in that state, and the next morning, the display was again frozen. This suggested that my memory was correct, and that it was infact a software problem. However, the following morning, after again leaving the unit in min-max display overnight, the problem didn’t present itself. So, it seems that I still don’t have it figured out. If so, it will suggest that some of the problems are the result of bad solder joints that act up when the unit is coming to a new thermal equilibrium. I also need to investigate the resistance and ACV functions. I’d also like to investigate its ability to use an external voltage reference to provide high-precision comparisons between different voltage standards. Doing so will require either figuring out a source of the (likely expensive) low-thermal-EMF rear panel connectors, or replacing them with similar performance and lower cost. Bookmark the permalink.Probably some variety by Loctite if I remember correctly. Notify me of new posts by email. Learn how your comment data is processed. Create one here. Creators are allowed to post content they produce to the platform, so long as they comply with our policies. United Kingdom. Company number 10637289. Search results for: (found: ) ask for a document File Date Descr Size Popular Mfg Model: Found in chassis2model: Found in repair tips. Mfg - DATRON. Note - Digital Multimeter THE DATRON AUTOCAL 1062, 1061 A and 1061 Autocal instruments 1061, 1061 A and 1062. For operating procedures refer to the User's Handbook. For any assistance contact your nearest Datron Sales and Service center. Addresses can be found at the back of this handbook. Due to our policy of continuously updating our products, this handbook may contain minor differences in specification, components and Amendment sheets precisely matched to your instrument serial number are available Section Title Page A3. 3. 2 Preamplifier and Scaling A27. A3. 3. 3 RMS Converter A28. A3. 3.4 High Frequency Compensation A29. A3. 3. 5 Frequency Detection A29. A3.3.6 Test A29 Page Oft Oft Simplified Resistance Assembly.. Oft An An The purpose of calibration is to take account of any The period between calibrations depends upon the The calibration procedures presented in the following Service Section. Temperature - So that the instrument can meet its In addition, temperature gradients around the instrument Warm up - It is essential that the instrument has Therefore, at least a 2 hour Calibration Source - To perform a useful calibration With some calibration sources, the output may take Guarding - It is preferable to arrange for the DVM Furthermore If a 'Remote Guard' connection is necessary then examples The Datron 'AUTOCAL' process means that complete In the process, an internal non-volatile memory stores Internally, each of the Access to the non-volatile memory is gained using When calibration is Insert the key into the 'CALIBRATE ENABLE' If the instrument is fitted with Option 50 IEEE Bus, Ib - This nulls the input bias current of the DC It can be operated as It should only be It must be used This is an extension of the 'AUTOCAL' process This means for Each of the five calibration operations can be control- This means that the More details On each range a 'Zero' and 'Gain' calibration is The two 'Zero' calibrat- If the 'DVM Reading After Calibration' is not in Where no tolerance If during calibration 'Error 4' is displayed, this indi- Under these circum- In the case of 'Zero', 'Gain' or 'AcHf' the Calibration. Source should be checked and the same 'CALIBRATE' If 'Error 4' Section or the Servicing Section of this Handbook. Datron products, number 400391 and 400392, are Autocal Standard. To check the accuracy after 'AUTOCAL' the 'Specification. Verification' section of the User's Handbook will be useful; Calibration. Operation. Calibration. Source. Output DVM Reading. After. Remarks Source Disable Cal. on completion SRQ service routine to read Calibration. Source Bus. Controller. Instruction. DVM Reading. Remarks In Remote. State Program DVM to Program DVM to. Function:DC V(F3). Range:1V (R3). SRQ Mode 1 (Q1). Enable Cal. (W1) Zero. In Remote. State. Program 'Zero' cal. SRQ indicates when Full Range State SRQ indicates when Internal. Trigger. Disable Cal. Program DVM to. Internal Trigger (T0). Disable Cal. (W0) Calibration key DVM in normal mode, Earth screening The two side and centre All the main circuit boards are mounted on the inner The Analog output circuitry is fixed on to the rear pcb of The chassis is mounted on to the side extrusions with For the purpose of explanation, each assembly will The Analog assembly is split into three distinct The Analog Interface receives data from the Digital Messages between the. Analog and Digital assemblies are passed via opto-isolators, The DC Isolator includes the preamplifier, range The Analog Interface provides electrical isolation Latched data At power-on the A - D converter is placed into the. RESET condition (See Section 3. 2. 3. 8). The analog cir- To determine which options are fitted the Digital Looking at the procedure, in more detail, the Analog. Interface Data (ID) lines are all set to a logic '1'except one, ID1 is set low, the rest of The opto-isolators invert all R55 from Ml 7-3, causing M19-3 to be high, producing a ID line low. Pin No. of M19 Option incorporated COND. VAL (M2-8) is high, signalling to the Digital Similarly, when the COND. VAL to be set high. AD lines. The next step in the power-up sequence as far as the IA0 line returns to the resting state of logic '1'. Thirdly, Once DC has been selected, the F.E.T. pattern latch is IA1 going low. The final step is to reselect DC as described Before the start of each reading, the analog interface The series of events is the Measurement. Circuits Selected. Use of D - A. DC Volts. Analog Assembly. Input Bias Current. Compensation. AC Volts. AC Assembly. Frequency Compensation. AC -H DC Volts. Resistance. Ohms Assembly Analog Assembly. DC Current. Current Assembly Analog Assembly. AC Current. Current Assembly Frequency Compensation. AC -1- DC Current. The update sequence order is (i) Deselect all assemblies, Isolator, (iv) Load range pattern into DC or AC range Note: Steps (v) and (vi) are used only when I or 12 is Appendix 1. When TEST is selected, a logic '0' is placed on ID7 Appendix 1 lists Figure 3.8 shows the essential features of the iso- For the purpose of explanation the RANGE position. Binary coded. D-A data —. See Appendix 1 Range. Gain Reference should be made to circuit diagram number Sheet 2 gives When the 100V or IkV range is selected, a —100, This is a matched set of re- The selection of a The amplifier end of the resistors is clamped by The output from the DC Isolator, test point (TL8) R111 and Q6, an attenuator chain of IV Range Q10 and Q8 are turned on, all other. F.E.T.'s are turned off and RL1 energised. The output of the amplifier is connected R110, R111 and Q10, an attenuator The preamplifier is designed to present an input Q12 is a well matched monolithic NPN transistor To compensate Thus the input bias current is Bootstrapped supplies are generated which track the M32 is the high inpedance buffer which tracks the The offset of M32 is Selection of DC(M20-3) enables the capacitive The positive bootstrap supply (h-BS) is generated as Q27, referenced to D50. When the output voltage of the Q27 conducts current into R175. Since the current in R175 The negative bootstrap supply (— BS) is generated Selection of filter causes an active filter to be switched The filter gives an attenuation Vi During the calibration cycle, the microprocessor When DC is selected, The output from the latches is applied to the binary The analog signal is applied to the The transistor of The other half of the opto-isolator acts as a current R129 to null the bias current of the preamplifier. During the self-test routine, (actuated from the The circuitry is placed into RL1 is not energized, (i.e. the -I- 100 attenuator is across Filter is selected and F.E.T. Q5 Thus a signal This signal is then measured and' compared with a stored Range. Output signal from DC Isolator Section 1 and Fig. 1.2 of the User's Handbook The technique used in the Autocal. Voltmeter is a quadruple slope, the two extra slopes being Fig. 3.12 is a simplified diagram showing the essent- Multiplexer Buffer. Integrator Detector Detector Assembly. Reset Switch. Control. Polarity Sense. From Digital Assembly Lines. Sig. Output TPB -Ref 2 Integrator.-p. Output Detector I. Output I Supply. The analog signal from the DC Isolator is applied to Control of the multiplexer is derived from the Digital volts) supply the defined current for the reference These signals zeners via R212 and R38 respectively. R19 and R18 The multiplexer is then R68 and R214, R70 respectively. The power supplies for the logic circuits M35, IVI29. M27, IV128 and opto-isolators Ml, M4, M5 and M6 are also Negative signa. Logic levels: (C C22 slows the switching edges from the multiplexer. M35 so that the buffer cannot slew-limit and thus lose the R11-R15) being bootstrapped to the output of the buffer, The basic Integrator comprises R6, R7 and C9, with FET-pair Q35 also has low gate leakage, which maintains An inverted and attenuated version of the integrator This is applied via. R4 and CIO to compensate for the small amount of The value of R5 is factory- C11 and R27 provide shorter term compensation. R23 being set to correct linearity at 10 of full range. The 1st null detector comprises a low noise amplifier. M22, an inverting configuration, where the dc gain is con- D3, prevent the amplifier from saturating. During REF 1 the non-inverting input is offset by REF 2 is applied (after counting is synchronised). In REF 2 The signal from the 1st null detector is applied to. Ml 5 which boosts the voltage gain. The output provides AC Option 12, or Ohms selected) the second null detector At the end of a measurement cycle or in hold, the The control lines R60 to a sample and hold capacitor Cl 2 on the integrator. Thus, with the input to the A - D converter at zero The reset signal applied to M26 pins 6 and 13 merely The preamplifier buffers and ranges the signal in Once converted to an equivalent DC signal, it is The conversion technique is electronic true RMS Relay RL2 is energised on selection of AC, directly AC coupling capacitor, to be by -passed. The signal is then fed to the switched gain inverting A simplified diagram of this arrangement is shown in Fig. Residual errors are removed The preamplifier has a stable DC path provided by F.E.T.'s Q32 and Q34. Further gain is provided by the Q15 and Q16 R121 compensates for the bias The unity gain frequency compensation amplifier AC path provided by Q25 to Q29. The bootstrap circuit of. Q19 presents the varicap diode. Dll, with a high imped- The RMS converter takes the scaled AC signal from The conversion M8 and M9 form a summing type, full wave recti- This forces a full- The output current from the RMS module passes Q1 and Q2 switch in additional The output of M1 (TP2) is fed to a resistor chain. R1 - R7, to provide an output of 3.14 volts by the selection Q3 is turned on when AC is selected Analog-to-Digital Converter (Drawing No, 430328 sheets 3 During the calibration cycle, the microprocessor The voltage produced is The varicap is thus adjusted to give The calibration is carried out at one H.F. frequency It should be noted Digital Board via M18, M2 (Drawing No. 430328 sheet During the self-test routine (actuated from the front The circuitry is placed into This signal is then meas- If the measured Range A3. 3.1 General Principles. The preamplifier buffers and ranges the signal in Once converted to an equivalent DC signal, it is The conversion technique is electronic true RMS A3. 22. The Datron RMS module can be best considered as Vx which is then filtered so that all the AC components are When the AC option is selected, the AC preamplifier Relay RL2 is energized on selection of AC, directly If DC and AC are selected together, the AC assembly The signal is then fed to the switched gain inverting A3. 23. The frequency response is held flat, to within Residual errors are DC to above 1MHz. Its input buffer Q36 reduces bias M22 output (Test link TLK) is fed To ensure stability at the The unity gain frequency-compensation amplifier The bootstrap circuit The RMS converter takes the scaled AC signal and The technique used is Electronic. True RMS Sensing as shown in the simplified block diagram. Fig. A3. 25. M13 and M14 form a summing full-wave rectifier. The output of precision half-wave rectifier M13 is summed Potentiometer. R62 adjusts the rectifier symmetry to provide the same The output current from the RMS module drives the Ml 6 is the active element of a switched 3-pole. Bessel filter. Ml 5 and Ml 7 switch the time constants, The high impedance output from the 3-pole filter is D26 and D16 prevent the voltage RMS computation in Ml 1. When the AC, or DC-coupled AC option is selected. Q3 connects the buffer output to the Analog-to-Digital A3.3.4 High Frequency Compensation. During the calibration cycle, the microprocessor The voltage produced is fed to The calibration is carried out at one H.F. frequency It should be noted A3. 3. 5 Frequency Detection (430552 sheet 2). The signal frequency is monitored by M10 which is Digital Board via Ml 8, M2 (Drawing No. 430328 sheet 5) A3. 3.6 Test. During the self-test routine (actuated from the front The circuitry is placed into the Thus a signal of approximately This signal is then measured and compared with a stored Range Output from RMS section The converter can be split into two When OHMS is selected, the front panel Lo terminal RL1 such that the voltage at front panel Lo is at reference. This voltage Q10 input bias current Thus if we consider 2-wire measurement, I-i- is linked Lo terminal is maintained at OV, Therefore the Hi terminal. As long as the error is small referred to reference 0, the. DVM will read the correct resistance. Input protection is provided as follows:- Open circuit voltage limit protection. I-t R15, R16, Q6, 07 Seven decades of ohms ranges are provided by 6 M5. Thus when gates B and C of M5 are open, C9 is These gates then Current. Current. Selector. Leakage path i Thus the current required for a particular range is selected Q4, Simplified diagram Fig. 3.30 shows the resistor chain On the high resistance ranges To produce good common mode rejection, M4 The filtered bootstrap supplies The use of ohms guard permits in-circuit measurement Consider Fig. 3.31. Guard is reference 0, Lo is actively maintained within During the self-test routine (actuated from the front The circuitry is placed into Thus with I-t The Current assembly contains a set of selectable Precision current shunts of 0.112, ir2, 9f2, 90r2 and To eliminate errors in measurement ACI. The latter, DC coupled mode, computing the RMS These circuits are placed in the MV range' amplifying the Overload protection up to 2 amps is provided by During the self test routine, the Current assembly is The circuitry is placed into Filter is selected H-15V supply. Thus a voltage of approximately 0.3 volts is This voltage combined with the effect of the voltage No. 430307). DVM. When Rear Input is selected either remotely or on When Front Input is selected, either remotely or on Thus relays RL1 and. RL2 are energised, causing the front signal input terminals Rear Input be selected, relays RL1 and RL2 are de- During the last part of the analog interface update The signal Input' lines are connected to the measurement circuits by When TEST is selected, the ratio option is checked to The Analog Output Board accepts the DC Isolator or A 6800 microprocessor (MPU) together with 16k Digital and Memory Error read-out specific- The 3.16V full range signal from the DC Isolator or. AC Converter is buffered by unity gain amplifier M2. The Potentiometer R5 is adjusted to remove any offset caused Output external connector. Calibration Memory Memory Max-Min stores. Limit The Digital assembly contains the circuitry providing The system uses the technique of a looping prioritised Program Modules: The program memory is split into OOTI. I 08 i. UPDATE MAm. OR Tin value Vt— CjATA value CC'MPuTe. LiMir CHECK filONLy. SET OvERuOAD FHtT angle projection PROGtRAM source A second stream, asynchron- Note that a The consumer is activated by a flag, Process Control. Control of the instrument by the The major system state A-B, -f-C, etc.). The pipeline comprises three levels. The top, Additionally, at this time, the level 1 to level 2 transfer is A second control mechanism used is to input all the Thus the processor under The 6800 requires a non-overlapping positive two- This is derived from the line-locked If data is not being trans- The circuit utilizes the propagation delays inherent in. M54 and M55 (approx. 10ns per gate), to ensure that the The decoded address The combined Each ROM is able to store up to 4096, 8-bit 'bytes' of MPU accesses a byte by placing its address on the 16-bit. Address Bus and driving the Valid Memory Address (VMA) Data Bus. The chip-select inputs for the RAM and ROM are A15.A13.A12 so that it covers the memory locations from. The processor employs 1024 bytes of 8-bit wide. Random Access Memory (RAM) made up from two 1024. M31 and M36 are employed as Since A8 and A9 are not. A further 256 bytes of 8-bit wide RAM are made up. M19 and M20 are Three address bits A12, A14 MPU via Q16. (See Fig. 3.38). During a power-up or power-down (-t5V supply line The Intrument is returned to the. HOLD mode with the last selected Alteration to a different Adjust L2 (Digital NOTE: This signal contains about 200mV peak-to-peak Links should be 22 SWG TIN.Cu wire with silicone Therefore great During manufacture certain. Value) to accommodate circuit component tolerances, or The thermal tracking of the DC Preamplifier is part- This rather time consum- NOTE: A routine calibration as detailed in Section CAUTION: Up to 260 volts is present inside the Equipment Requirements. Variable 5V, 1 amp DC supply Autocal Standard. Procedure. Power Supplies Digital assembly. Adjust R2 on the Rear (Power Digital Assembly Lo's to TP28. Reduce supply to 4.750V -t-10mV. Connect oscilloscope Lo to. TP28 and monitor M53 pin 40. Turn R83 anti-clock- Switch on the instrument. TP25, Lo to TP28. Adjust scope trigger until the Connect oscilloscope. NOTE: This signal contains about 200mV peak to NOTE: The display CAL legend will be lit. NOTE: All the calibration store correction factors Analog Assembly (DC Isolator Section) Connect DVM Hi to TL8, Lo to TP20. Adjust FSV R152 with a metal film resistor If reading C—50 aiV, reselect FSV resistor R39 NB R39 and R40must each be at least 100 kilohms. Disconnect the. DVM leads, and the connections from the front panel. The basic Ohms set-up procedure is now complete. Equipment Required: DC calibrator, e.g. Datron 4000 or 4000A. AC calibrator, e.g. Datron 4200. Procedure Short Hi to Lo. Connect DVM Hi to TL7, Lo to TP8 and note read- Connect oscilloscope Hi Remove the oscillo- R75 (linearity) for an indication on the DVM of Connect DVM Hi to TL5, Lo to TPS. If reading is Make links TL1 to TL4 if cut. Switch on instrument, Consult Fig. 4.2 Check voltage on TL5 is Lo.