Loading ...
Sorry, an error occurred while loading the content.
 

Input for my dotting chart recodrer.

Expand Messages
  • g8voq
    I ve got an analogue dott/dotting chart recorder, and the paper moves at 10/20/40mm per hour. FSD occurs at 10mV. There are 6 channels. If I wanted to feed a
    Message 1 of 23 , Dec 8, 2012
      I've got an analogue dott/dotting chart recorder, and the paper moves at 10/20/40mm per hour. FSD occurs at 10mV. There are 6 channels.

      If I wanted to feed a channel with a signal emanating from a temperature sensor, I suppose I'd connect a thermocouple to the recorder.

      Would I need some sort of conditioning circuitry between a themocouple and the recorder input? Thanks.
    • Derek
      Ideally yes. But properly you need to know two key things. 1. Output voltage range of your temperature sensor, assuming the thermocouple is already buffered to
      Message 2 of 23 , Dec 8, 2012
        Ideally yes. But properly you need to know two key things.

        1. Output voltage range of your temperature sensor, assuming the thermocouple is already buffered to provide an output voltage versus measuring the resistance.

        2. Input voltage range of your recorder.

        Then the only thing is to convert the temperature sensor output to satisfy the range of the chart recorder.

        Without knowing the two things above it is difficult to start the design.

        Derek Koonce
        DDK Interactive Consulting Services



        --- In Electronics_101@yahoogroups.com, "g8voq" <hobby_electronics@...> wrote:
        >
        > I've got an analogue dott/dotting chart recorder, and the paper moves at 10/20/40mm per hour. FSD occurs at 10mV. There are 6 channels.
        >
        > If I wanted to feed a channel with a signal emanating from a temperature sensor, I suppose I'd connect a thermocouple to the recorder.
        >
        > Would I need some sort of conditioning circuitry between a themocouple and the recorder input? Thanks.
        >
      • g8voq
        I d be wanting to use the recorder to record outside temperature readings from a sensor 10m away. It would be reasonable to say that I d need the recorder to
        Message 3 of 23 , Dec 8, 2012
          I'd be wanting to use the recorder to record outside temperature readings from a sensor 10m away. It would be reasonable to say that I'd need the recorder to handle input from -20C to + 40C.

          That is a 60 degree range.

          I see that there are types of thermocouples. Type K is general purpose and sensitivity is 41uV/C. Therefore the voltage change from -20 to +40 would be 2.46mV. In this example, I may need conditioning so the range of voltage input was 10mV.

          I've not yet got a manual for the recorder. I note that there are adjustments for GAIN - DAMP - ZERO - SPAN.
        • g8voq
          Does anyone know what kind of sensor inexpensive digital indoor/outdoor thermometers use? Perhaps I ought to use one of those sensors. Not sure if they are
          Message 4 of 23 , Dec 8, 2012
            Does anyone know what kind of sensor inexpensive digital indoor/outdoor thermometers use?

            Perhaps I ought to use one of those sensors. Not sure if they are thermocouple, RTD, or some other type.
          • Howard Hansen
            ... One suggestion is a TMP36 semiconductor temperature sensor. See: It has a scale
            Message 5 of 23 , Dec 8, 2012
              On 12/8/2012 6:19 PM, g8voq wrote:
              >
              > Does anyone know what kind of sensor inexpensive digital
              > indoor/outdoor thermometers use?
              >
              > Perhaps I ought to use one of those sensors. Not sure if they are
              > thermocouple, RTD, or some other type.
              >
              > __

              One suggestion is a TMP36 semiconductor temperature sensor. See:
              <http://www.digikey.com/product-detail/en/TMP36GT9Z/TMP36GT9Z-ND/820404>

              It has a scale factor of 10 mv/(degree C), an output of 750 mv at 25
              degrees C and a sensing range of 40 degrees C to 125 degrees C.

              The other Howard


              [Non-text portions of this message have been removed]
            • smilingcat90254
              If you decide to use TMP36 load the output, vout, to ground with about 50K ohm resistor. If there is any stray current that wants to pull the output high,
              Message 6 of 23 , Dec 8, 2012
                If you decide to use TMP36 load the output, vout, to ground with about 50K ohm resistor. If there is any stray current that wants to pull the output high, TMP36 can't hold the voltage and the output will rail. Stray current required for this to happen is very small. I never measured, but my guess is that its around 1uA or less injected into the output.

                Another choice is MCP9700/MCP9700A. MCP9700A is bit more accurate. You can correct the "offset" fairly easily with one opamp, resistors and two trim pots. MCP9700s do not need a resistor on the output to ground.

                Sincerely,

                smilingcat

                --- In Electronics_101@yahoogroups.com, Howard Hansen <hrhan@...> wrote:
                >
                > On 12/8/2012 6:19 PM, g8voq wrote:
                > >
                > > Does anyone know what kind of sensor inexpensive digital
                > > indoor/outdoor thermometers use?
                > >
                > > Perhaps I ought to use one of those sensors. Not sure if they are
                > > thermocouple, RTD, or some other type.
                > >
                > > __
                >
                > One suggestion is a TMP36 semiconductor temperature sensor. See:
                > <http://www.digikey.com/product-detail/en/TMP36GT9Z/TMP36GT9Z-ND/820404>
                >
                > It has a scale factor of 10 mv/(degree C), an output of 750 mv at 25
                > degrees C and a sensing range of 40 degrees C to 125 degrees C.
                >
                > The other Howard
                >
                >
                > [Non-text portions of this message have been removed]
                >
              • David
                ... Before you even start to think about what kind of sensors or signal conditioning circuitry you need, you need to know more about the recorder. When you
                Message 7 of 23 , Dec 9, 2012
                  --- In Electronics_101@yahoogroups.com, Howard Hansen <hrhan@...> wrote:
                  >
                  > On 12/8/2012 6:19 PM, g8voq wrote:
                  > >
                  > > Does anyone know what kind of sensor inexpensive digital
                  > > indoor/outdoor thermometers use?
                  > >
                  > > Perhaps I ought to use one of those sensors. Not sure if they are
                  > > thermocouple, RTD, or some other type.
                  > >
                  > > __
                  >
                  > One suggestion is a TMP36 semiconductor temperature sensor. See:
                  > <http://www.digikey.com/product-detail/en/TMP36GT9Z/TMP36GT9Z-ND/820404>
                  >
                  > It has a scale factor of 10 mv/(degree C), an output of 750 mv at 25
                  > degrees C and a sensing range of 40 degrees C to 125 degrees C.
                  >
                  > The other Howard
                  >

                  ---

                  Before you even start to think about what kind of sensors or signal conditioning circuitry you need, you need to know more about the recorder. When you know the input characteristics of the recorder, then you can determine the sensors/conditioning circuitry.
                  What is the make and model or your recorder? Maybe someone in the group has a manual for it, or can help find a manual.
                  Without that info, you'll have to resort to experimentation. Get a stable power supply and a DVM, make a voltage divider with fixed resistor(s) and a potentiometer, and starting with millivolt levels, start feeding a signal into one of the inputs until the needle starts to respond (monitor the voltage with the DVM). Increase the voltage until the needle goes to full scale. When you know the limits of each of the inputs, then you can start thinking about sensors and signal conditioning circuitry.
                  Remember, start with low millivolt levels into the recorder's inputs; otherwise, you risk damaging the recorder's input circuitry.
                  ---
                  Cheers,
                  Dave M
                • g8voq
                  ... Exactly. I need to first get a manual. I may get one soon from some chap I contacted. He is going to get back to me. Dot recorder is an old SEKONIC SS-100
                  Message 8 of 23 , Dec 9, 2012
                    --- In Electronics_101@yahoogroups.com, "David" <dgminala@...> wrote:
                    > Before you even start to think about what kind of sensors or signal conditioning circuitry you need, you need to know more about the recorder. When you know the input characteristics of the recorder, then you can determine the sensors/conditioning circuitry.
                    .....
                    ---
                    > Cheers,
                    > Dave M

                    Exactly. I need to first get a manual. I may get one soon from some chap I contacted. He is going to get back to me. Dot recorder is an old SEKONIC SS-100 SS100.

                    Found some design notes:

                    http://ww1.microchip.com/downloads/en/DeviceDoc/21895d.pdf
                  • Larry Beaty
                    The ones I have seen use a 10K NTR resistor. It does not run proportional with temperature and must be taken into account in your readout. Myself, I use four
                    Message 9 of 23 , Dec 9, 2012
                      The ones I have seen use a 10K NTR resistor. It does not run proportional
                      with temperature and must be taken into account in your readout.



                      Myself, I use four silicon diodes in series with 1 mA of current thru the
                      series diodes. Exactly linear with temperature and each diode gives -2.5
                      mV/C for a total with four diodes of approximately -10mV/C. the only
                      problem is to set your readout to pickup the voltage where you want to start
                      the temperature measurement - zero point. But your chart recorder has an
                      offset control that would fix that point.



                      Larry



                      From: Electronics_101@yahoogroups.com
                      [mailto:Electronics_101@yahoogroups.com] On Behalf Of g8voq
                      Sent: Saturday, December 08, 2012 7:20 PM
                      To: Electronics_101@yahoogroups.com
                      Subject: [Electronics_101] Re: Input for my dotting chart recodrer.





                      Does anyone know what kind of sensor inexpensive digital indoor/outdoor
                      thermometers use?

                      Perhaps I ought to use one of those sensors. Not sure if they are
                      thermocouple, RTD, or some other type.





                      [Non-text portions of this message have been removed]
                    • g8voq
                      I m looking at the SS-100 manual: My dotting recorder has two rows of input connectors (6 channels): 1 2 3 4 5 6 + * * * * * * ----- Voltage or
                      Message 10 of 23 , Dec 10, 2012
                        I'm looking at the SS-100 manual:

                        My dotting recorder has two rows of input connectors (6 channels):

                        1 2 3 4 5 6
                        + * * * * * * -----
                        Voltage or Thermocouple
                        - * * * * * * -----

                        Input is 0- 10mV.

                        Section: Voltage & Thermocouple:

                        What seems clear is that:

                        I can place a voltage across + and -.

                        I can connect a thermocouple across + and -.

                        Okay, but I'm confused about a the other section:

                        Section: Platinum Resistance Bulb:

                        1 2 3 4 5 6
                        A * * * * * *
                        R
                        B * * * * * *
                        L
                        B * * * * * *

                        Manual shows a resistor R connected between 1 A and 1 B. And a link L between 1 B and 1 B. See above.

                        I'm confused because there are only two rows of connectors on my dotting recorder.

                        Specifications:

                        Input voltage: "DC 10mV. (Optional L 1mV,100mV, 1V, 5V, Thermocopule, Resistance Bulb, etc)."

                        Input resistance: more than 1M Ohm

                        Signal Resistance: less than 10 Kilo Ohms.

                        I'm not sure I can use Platinum Restance Bulb with my SS-100. But, one thinks I ought to be able to!
                      • Howard Hansen
                        Because you say the recorder only has 2 rows of input terminals it looks like the Platinum RTD capability is an option one has to specify at the time of
                        Message 11 of 23 , Dec 10, 2012
                          Because you say the recorder only has 2 rows of input terminals it looks
                          like the Platinum RTD capability is an option one has to specify at the
                          time of purchase. Many manuals are written to cover many different
                          versions of a product. Hence some parts of the manual may not apply to
                          a particular version of the product.

                          I suggest you get your feet wet. Hook up a TC to the recorder and check
                          the operation using an ice bath and boiling water. Don't forget you
                          will be measuring the difference in temperature between the reference
                          junction and the TC junction. For the above setup the reference
                          junction is the recorder's input terminals.

                          The other Howard




                          On 12/10/2012 1:30 PM, g8voq wrote:
                          >
                          >
                          >
                          > I'm looking at the SS-100 manual:
                          >
                          > My dotting recorder has two rows of input connectors (6 channels):
                          >
                          > 1 2 3 4 5 6
                          > + * * * * * * -----
                          > Voltage or Thermocouple
                          > - * * * * * * -----
                          >
                          > Input is 0- 10mV.
                          >
                          > Section: Voltage & Thermocouple:
                          >
                          > What seems clear is that:
                          >
                          > I can place a voltage across + and -.
                          >
                          > I can connect a thermocouple across + and -.
                          >
                          > Okay, but I'm confused about a the other section:
                          >
                          > Section: Platinum Resistance Bulb:
                          >
                          > 1 2 3 4 5 6
                          > A * * * * * *
                          > R
                          > B * * * * * *
                          > L
                          > B * * * * * *
                          >
                          > Manual shows a resistor R connected between 1 A and 1 B. And a link L
                          > between 1 B and 1 B. See above.
                          >
                          > I'm confused because there are only two rows of connectors on my
                          > dotting recorder.
                          >
                          > Specifications:
                          >
                          > Input voltage: "DC 10mV. (Optional L 1mV,100mV, 1V, 5V, Thermocopule,
                          > Resistance Bulb, etc)."
                          >
                          > Input resistance: more than 1M Ohm
                          >
                          > Signal Resistance: less than 10 Kilo Ohms.
                          >
                          > I'm not sure I can use Platinum Restance Bulb with my SS-100. But, one
                          > thinks I ought to be able to!
                          >
                          >



                          [Non-text portions of this message have been removed]
                        • g8voq
                          I think it must be that all my recorder does is accept an input voltage of 0-10mV. That allows direct connection of a thermocouple. Connecting a 3 wire
                          Message 12 of 23 , Dec 10, 2012
                            I think it must be that all my recorder does is accept an input voltage of 0-10mV.

                            That allows direct connection of a thermocouple.

                            Connecting a 3 wire configuation with RTD with no external circuitry would require the bridge to be within the recorder.

                            So, since I only have + and - input (also GND) it appears the only way I could employ a 3 wire conguration with RTD is to construct an external bridge cicuit and feed the bridge output to the + and - terminals of my recorder.

                            That how I see things.

                            No idea why in the SS-100 manual, there is a drawing showing three rows of inputs. Unless that is a variant of SS-100.

                            http://en.wikipedia.org/wiki/Resistance_thermometer
                          • g8voq
                            Hi. Yep, that is the conclusion I was moving towards. That it was an order option to have 3 inputs. Three inputs would be associated with 3 wire configuration
                            Message 13 of 23 , Dec 10, 2012
                              Hi.

                              Yep, that is the conclusion I was moving towards. That it was an order option to have 3 inputs. Three inputs would be associated with 3 wire configuration RTD. Bridge would be inside the recorder.

                              Rich

                              --- In Electronics_101@yahoogroups.com, Howard Hansen <hrhan@...> wrote:
                              >
                              > Because you say the recorder only has 2 rows of input terminals it looks
                              > like the Platinum RTD capability is an option one has to specify at the
                              > time of purchase. Many manuals are written to cover many different
                              > versions of a product. Hence some parts of the manual may not apply to
                              > a particular version of the product.
                              >
                              > I suggest you get your feet wet. Hook up a TC to the recorder and check
                              > the operation using an ice bath and boiling water. Don't forget you
                              > will be measuring the difference in temperature between the reference
                              > junction and the TC junction. For the above setup the reference
                              > junction is the recorder's input terminals.
                              >
                              > The other Howard
                            • g8voq
                              I m assuing Platinum resistance bulb means RTD.
                              Message 14 of 23 , Dec 10, 2012
                                I'm assuing Platinum resistance bulb means RTD.
                              • Howard Hansen
                                ... In industry you will frequently see Platinum temperature sensors referred to as Platinum RTD where RTD stands for resistance temperature detector. The
                                Message 15 of 23 , Dec 10, 2012
                                  On 12/10/2012 4:09 PM, g8voq wrote:
                                  >
                                  >
                                  > I'm assuing Platinum resistance bulb means RTD.
                                  >

                                  In industry you will frequently see Platinum temperature sensors
                                  referred to as Platinum RTD where RTD stands for resistance temperature
                                  detector.

                                  The other Howard


                                  [Non-text portions of this message have been removed]
                                • g8voq
                                  Okay, a retired guy from Sekonic confirmed that my SS-100 only accepts a two wire input of between 0-10mV. So the specs for the recorder are: Input voltage: DC
                                  Message 16 of 23 , Dec 10, 2012
                                    Okay, a retired guy from Sekonic confirmed that my SS-100 only accepts a two wire input of between 0-10mV.

                                    So the specs for the recorder are:

                                    Input voltage: DC 10mV.

                                    Input resistance: more than 1M Ohm

                                    Signal Resistance: less than 10 Kilo Ohms.

                                    Not sure what the last two specs mean, well ceretsainly the last one. Input suppossed to be DC.

                                    I was thinking of trying to use an RTD sensor. That would require an external circuit of some type I have not yet identified.


                                    --- In Electronics_101@yahoogroups.com, "g8voq" <hobby_electronics@...> wrote:
                                    >
                                    > I think it must be that all my recorder does is accept an input voltage of 0-10mV.
                                  • Howard Hansen
                                    Here is an application note that starts with the design of a Wheatstone Bridge signal conditioner for a Platinum RTD. See Figure 1 in the application note.
                                    Message 17 of 23 , Dec 11, 2012
                                      Here is an application note that starts with the design of a Wheatstone
                                      Bridge signal conditioner for a Platinum RTD. See Figure 1 in the
                                      application note.
                                      <http://www.egr.msu.edu/classes/ece480/capstone/fall11/group05/docs/app%20notes/Application%20note-Minjae.pdf>
                                      The application note then adds modifications to the design when a higher
                                      amplitude output is required. Seeing as you have a strip chart
                                      recorder designed for mv signals you can skip that part of the PDF.

                                      The other Howard



                                      On 12/10/2012 11:51 PM, g8voq wrote:
                                      >
                                      > Okay, a retired guy from Sekonic confirmed that my SS-100 only accepts
                                      > a two wire input of between 0-10mV.
                                      >
                                      > So the specs for the recorder are:
                                      >
                                      > Input voltage: DC 10mV.
                                      >
                                      > Input resistance: more than 1M Ohm
                                      >
                                      > Signal Resistance: less than 10 Kilo Ohms.
                                      >
                                      > Not sure what the last two specs mean, well ceretsainly the last one.
                                      > Input suppossed to be DC.
                                      >
                                      > I was thinking of trying to use an RTD sensor. That would require an
                                      > external circuit of some type I have not yet identified.
                                      >
                                      > --- In Electronics_101@yahoogroups.com
                                      > <mailto:Electronics_101%40yahoogroups.com>, "g8voq"
                                      > <hobby_electronics@...> wrote:
                                      > >
                                      > > I think it must be that all my recorder does is accept an input
                                      > voltage of 0-10mV.
                                      >
                                      >



                                      [Non-text portions of this message have been removed]
                                    • g8voq
                                      I m actually wondering if I should go for a current loop system and employ XTR105 current loop transmittter (with RTD) and RCV420 current loop reciever. Or
                                      Message 18 of 23 , Dec 14, 2012
                                        I'm actually wondering if I should go for a current loop system and employ XTR105 current loop transmittter (with RTD) and RCV420 current loop reciever. Or similar ICs.

                                        --- In Electronics_101@yahoogroups.com, Howard Hansen <hrhan@...> wrote:
                                        >
                                        > Here is an application note that starts with the design of a Wheatstone
                                        > Bridge signal conditioner for a Platinum RTD. See Figure 1 in the
                                        > application note.
                                        > <http://www.egr.msu.edu/classes/ece480/capstone/fall11/group05/docs/app%20notes/Application%20note-Minjae.pdf>
                                        > The application note then adds modifications to the design when a higher
                                        > amplitude output is required. Seeing as you have a strip chart
                                        > recorder designed for mv signals you can skip that part of the PDF.
                                        >
                                        > The other Howard
                                        >
                                      • Howard Hansen
                                        ... I don t know what the price of a XR 105 is but if it s within your budget it is a good way to go. You don t need a RCV 420 receiver. All you need to do is
                                        Message 19 of 23 , Dec 16, 2012
                                          On 12/14/2012 2:43 PM, g8voq wrote:
                                          >
                                          >
                                          >
                                          > I'm actually wondering if I should go for a current loop system and
                                          > employ XTR105 current loop transmittter (with RTD) and RCV420 current
                                          > loop reciever. Or similar ICs.
                                          >

                                          I don't know what the price of a XR 105 is but if it s within your
                                          budget it is a good way to go. You don't need a RCV 420 receiver. All
                                          you need to do is connect a 0.5 ohm resistor and the current loop
                                          signal to the input terminals of the chart recorder. By doing this the
                                          4 to 20 mA output of the transmitter will develop a 0.2 to 10 mV signal
                                          across the input of the chart recorder. I believe way back at the
                                          beginning of this thread you said the chart recorder's full scale
                                          deflection was 10 mV.

                                          The other Howard

                                          PS
                                          The XTR105 is a monolithic 4-20mA, 2-wire current transmitter
                                          with two precision current sources. It provides complete
                                          current excitation for platinum RTD temperature sensors and
                                          bridges, instrumentation amplifiers, and current output circuitry
                                          on a single integrated circuit.





                                          >
                                          > --- In Electronics_101@yahoogroups.com
                                          > <mailto:Electronics_101%40yahoogroups.com>, Howard Hansen <hrhan@...>
                                          > wrote:
                                          > >
                                          > > Here is an application note that starts with the design of a Wheatstone
                                          > > Bridge signal conditioner for a Platinum RTD. See Figure 1 in the
                                          > > application note.
                                          > >
                                          > <http://www.egr.msu.edu/classes/ece480/capstone/fall11/group05/docs/app%20notes/Application%20note-Minjae.pdf>
                                          > > The application note then adds modifications to the design when a
                                          > higher
                                          > > amplitude output is required. Seeing as you have a strip chart
                                          > > recorder designed for mv signals you can skip that part of the PDF.
                                          > >
                                          > > The other Howard
                                          > >
                                          >
                                          >



                                          [Non-text portions of this message have been removed]
                                        • g8voq
                                          http://www.ti.com/lit/ds/symlink/xtr105.pdf Yep, I see that at figure 1 on page 7. Formula for RL at bottom left page 9. I wonder though if V+ should be Vps in
                                          Message 20 of 23 , Dec 17, 2012
                                            http://www.ti.com/lit/ds/symlink/xtr105.pdf

                                            Yep, I see that at figure 1 on page 7.

                                            Formula for RL at bottom left page 9.

                                            I wonder though if V+ should be Vps in that formula.



                                            --- In Electronics_101@yahoogroups.com, Howard Hansen <hrhan@...> wrote:
                                            >
                                            > On 12/14/2012 2:43 PM, g8voq wrote:
                                            > >
                                            > >
                                            > >
                                            > > I'm actually wondering if I should go for a current loop system and
                                            > > employ XTR105 current loop transmittter (with RTD) and RCV420 current
                                            > > loop reciever. Or similar ICs.
                                            > >
                                            >
                                            > I don't know what the price of a XR 105 is but if it s within your
                                            > budget it is a good way to go. You don't need a RCV 420 receiver. All
                                            > you need to do is connect a 0.5 ohm resistor and the current loop
                                            > signal to the input terminals of the chart recorder. By doing this the
                                            > 4 to 20 mA output of the transmitter will develop a 0.2 to 10 mV signal
                                            > across the input of the chart recorder.
                                          • g8voq
                                            That formula is for Rmax by the way, not the value of resistor I d need, which as you say would bw 0.5R.
                                            Message 21 of 23 , Dec 17, 2012
                                              That formula is for Rmax by the way, not the value of resistor I'd need, which as you say would bw 0.5R.

                                              --- In Electronics_101@yahoogroups.com, "g8voq" <hobby_electronics@...> wrote:
                                              >
                                              > http://www.ti.com/lit/ds/symlink/xtr105.pdf
                                              >
                                              > Yep, I see that at figure 1 on page 7.
                                              >
                                              > Formula for RL at bottom left page 9.
                                              >
                                              > I wonder though if V+ should be Vps in that formula.
                                            • g8voq
                                              I m now thinking of wireless! Not sure how to implement that. Maybe I ll find an IC.
                                              Message 22 of 23 , Dec 17, 2012
                                                I'm now thinking of wireless! Not sure how to implement that. Maybe I'll find an IC.
                                              • Howard Hansen
                                                ... I agree with you. The formula makes more sense if Vps is used in place of V+. The other Howard ... [Non-text portions of this message have been removed]
                                                Message 23 of 23 , Dec 17, 2012
                                                  On 12/17/2012 12:44 PM, g8voq wrote:
                                                  >
                                                  > http://www.ti.com/lit/ds/symlink/xtr105.pdf
                                                  >
                                                  > Yep, I see that at figure 1 on page 7.
                                                  >
                                                  > Formula for RL at bottom left page 9.
                                                  >
                                                  > I wonder though if V+ should be Vps in that formula.
                                                  >

                                                  I agree with you. The formula makes more sense if Vps is used in place
                                                  of V+.

                                                  The other Howard


                                                  >
                                                  > --- In Electronics_101@yahoogroups.com
                                                  > <mailto:Electronics_101%40yahoogroups.com>, Howard Hansen <hrhan@...>
                                                  > wrote:
                                                  > >
                                                  > > On 12/14/2012 2:43 PM, g8voq wrote:
                                                  > > >
                                                  > > >
                                                  > > >
                                                  > > > I'm actually wondering if I should go for a current loop system and
                                                  > > > employ XTR105 current loop transmittter (with RTD) and RCV420 current
                                                  > > > loop reciever. Or similar ICs.
                                                  > > >
                                                  > >
                                                  > > I don't know what the price of a XR 105 is but if it s within your
                                                  > > budget it is a good way to go. You don't need a RCV 420 receiver. All
                                                  > > you need to do is connect a 0.5 ohm resistor and the current loop
                                                  > > signal to the input terminals of the chart recorder. By doing this the
                                                  > > 4 to 20 mA output of the transmitter will develop a 0.2 to 10 mV signal
                                                  > > across the input of the chart recorder.
                                                  >
                                                  >



                                                  [Non-text portions of this message have been removed]
                                                Your message has been successfully submitted and would be delivered to recipients shortly.