Common Questions

This page contains some of the more frequently asked questions, concerning our syringe pumps. If you have other questions that are not addressed here, please contact us.

  • How many PSI does the pump generate ?

    (or alternately: How much pressure does the pump generate ?)

    The KDS-100 can generate up to about 20 pounds of linear force, and the KDS-200 series can generate up to about 40 pounds of linear force. This is not the same as PSI (pounds per square inch) which is an area measurement. The psi is dependent on the application (such as the viscosity of the liquid, presence and amount of capillary tubing, size of the syringe, etc., so it is impossible to estimate the psi without specific details of your application.

    For an application where only a syringe is needed, you can use the data below to approximate the psi generated by the force of the pusher block:

    As a first approximation, the pressure is the force pushing on the syringe plunger [lb] divided by the cross-sectional area of the syringe [in2]. Therefore, the smaller the syringe the higher the pressure.
    Pressure units = lbs / in2 (psi).
    Force generated by the KDS100 is at least 20 lbs.

    KDS200 with a single syringe: Pressure = force 40 lb / syringe cross-sectional area.
    Example: Calculate pressure for 20 ml syringe where Barrel ID = 20 mm

    Pressure Equation
  • How do I check my pump for proper calibration ?

    Calibration check for syringe pumps:

    1. Set the diameter for 26.7 mm.
    2. Set the rate for 5.6 ml / hour.
    3. Place the pusher block approx. One inch from the left , near the pulley cover.
    4. Run the pump for a few seconds. This will lock the ½ nut into the lead-screw.
    5. Stop the pump and measure the distance between the pusher block and the pulley cover. Use a dial or digital caliper.
    6. Run the pump for one hour.
    7. Measure the distance between the pusher and pulley cover again.
    8. The difference between the two numbers should be 1.00 cm.
  • What do I do if the pump isn't dispensing accurately ?

    If after running the calibration test, you determine the values are not within requirements or specifications, you should return the pump to the manufacturer for calibration/repair. Generally this involves tightening the belts, replacing worn hardware, etc. More details on repair actions can be found in that section of the KDS Web site.

  • I'm having trouble communicating via the RS-232 port.

    Troubleshooting the communications process is a relatively simple matter. The three components of the problem are the pump, the computer, and the cable between the two.

    1. Configure the Pump – Set the pump RS232 settings.
    2. Verify the cable is working properly. You should see "remote" in the display of the pump after you have sent the pump a command from the computer. If not, you should check your cable The pumps use simple three wire communications - ground, transmit, and receive. No flow control. No handshaking.
    3. Configure the program to the same RS232 setup as the pump. We recommend you test the communication by using Hyperterminal in Windows.

    RS232 Format

    8 data bits
    No parity
    1 stop (can use 2 stops)
    Pin Out

    PC with 9-pin connector PC with 25-pin connector
    data IN (pin 2) data IN (pin 3)
    data OUT (pin 3) data OUT (pin 2)

    Verification of RS232 communications using Windows® Terminal/Hyperterminal

    Use two Windows® programs to check the interface:
    1. Terminal in Windows® 3.1
    2. Hyperterminal in Windows® 95 & 98, XP

    Hyperterminal Settings
    In Properties set to "direct to COM 2" or appropriate COM port number
    Configure 9600 data bits/sec (baud rate must be same in pump)
      8 data bits
      none parity
      1 stop bits
      none flow control
    Settngs terminal key
      TTY emulation
      500 back scroll buffer
      echo typed
      0 time delay (possibly 100 millisecs)
      0 character delay (possibly 100 millicecs)
    Terminal Settings
    Terminal Emulation TTY generic
    Terminal Prefs line wrap - checked
      local echo
      cursor - block and blink
      terminal fone - fixedsys 15
      translations - none
      show scroll bars
      use function arrows
      buffer lines - 100
    Function Keys key level 1
    Text Transfer std flow control
    Binary Transfer X modem / CRC
    Communications baud rate 9600
      data bits 8
      stop bits 1
      parity none
      flow control none
      connector "COM 1"
    Modem Commands
    Prefix suffix
    Dial + ATDT ----------
    Binary Original ATQOVIE ISO Modem default: Hayes
  • What is the min/max flow rate for my pump ?

    Minimum and maximum flow rates are dependent on the size of the syringe you are using. Flow rates may be found on the specific product page, listed by model number and syringe size. And under the Technical Resources / Flow Rates menu.

  • Are spare parts available for the KD Scientific Pumps ?

    We strongly recommend that any repairs done to KD Scientific pumps be performed by KD Scientific technicians here at our facility. Typical spare part numbers are below.

    Part NumberItem Description
    KDS-100 Series Parts
    1000-015 Keypad
    1000-006 Drive nut (also called "half-nut")
    1000-024 PCB Assy
    1000-008 Pusher Block Assy. (contains drive nut)
    1000-100 Mechanism Kit (contains leadscrew, syringe holder block, etc)
    KDS-200 Series Parts
    2000-015 Keypad
    2000-006 Drive nut (also called "half-nut")
    2000-016 PCB Assy
    2000-050 Pusher Block Assy. (contains drive nut)

    * Please note: Different KDS-200 series pumps have different pusher block assemblies ! Please call for specific requirements !

  • My display shows a power failure.

    This is not a problem with the pump. It is indicating you lost power, similar to your digital clock flashing that you lost power. If you wish to turn this message off, go to the "PWR UP" mode in the menu and select "STOP".

  • My display shows NVRAM.

    Call the factory for more information.