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  • Merlin Universal Input Digital Indicator

    With Simple Setup via USB

    Merlin Universal Input Digital Indicator. Find out everything you need to know about the Define Instruments Merlin (No Output) in just 30 seconds with our quick video overview.
    Merlin (No Output)

    CUSTOMIZABLE PRODUCT: This product is available in custom configurations for OEMs and high volume orders (over 100 pieces). If you have a difficult application that requires our engineering input, please call 1-888-652-4757 so we can assist you.

    Output Options (Please Select)

    What it does:
    The Merlin accepts one of several popular input signal types to display.

    No more accidental changes during handling!

    With programmable panel meters one slip of the finger can be the root of many headaches. But with the Merlin you don’t have to worry! There’s no buttons on the unit so you don’t need to stress about accidental parameter alterations during handling. Instead set-up is via your PC using a USB connection.

    It doesn’t matter what voltage you’re using

    Sending to another country with a different voltage? Worried about the unit getting fried? Relax.

    The Merlin accepts 24-250V AC or 19.5-250V DC making it a truly universal unit suitable for anywhere in the world. So now there’s no need to stock separate high voltage and low voltage units, now you just need one: this one!

    So simple it doesn't need a manual

    It doesn't get much simpler than this. No more reading hefty manuals or frustrating delays. You'll experience the rare joy of getting your application up and running sooner and afterwards you'll wonder why you've tolerated difficult setups all this time.

    You don't need to power it up to configure

    Yes, you heard us correctly. You can configure the unit directly using the Merlin's excitation voltage. You'll be surprised how easy we've made it.

    In addition to this software a Bridge Key is required for the configuration of this product. You must order one unless you already have one from a previous product purchase.

    Compare digital indicators

    Brand & Model Power Supply
    Analog Out
    UL Listed?
    Red Lion PAXD000
    85-265 AC or 11-36V DC
    0/4-20mA or 0-10V
    Yes $403 
    Precision Digital Trident
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    Newport iSeries - i8A00
    90–265V AC or 12–36V DC
    0/4-20mA or 0-10V  
    Yes $295
    Define Instruments Merlin 19.5–265 (AC/DC)

    Prices checked Feb 28, 2017

    The Merlin process indicator accepts analog inputs from a range of industrial sensors, including: process, temperature, flow, frequency, and voltage from 200mV to 300V. It features a wide range power supply that suits both AC mains and 24V DC applications, and supplies the excitation required for common sensors and transmitters.

    The Merlin digital panel meter can be scaled into any engineering unit, and the result displayed on the large 0.8” 4 digit super-bright LED display. Auto ranging is available to increase the dynamic range of viewable data. The Merlin R2A adds two Form A 3 Amp relays for a variety of control and alarm functions, and a 4-20mA active output for retransmission to PLCs and SCADA systems.

    This panel indicator has been designed for harsh industrial environments. With an IP65 sealed bezel and extensive testing of noise effects to and beyond CE requirements, the Merlin LED panel meter provides a tough and reliable application solution.

    Universal input:

    • Temperature input
      Thermocouple (B/E/J/K/N/R/S/T types), RTD (Pt100/Pt1000), NTC (10K Beta 3984/3435)
    • Process input
      Current (0/4–20.000mA DC), Voltage (various ranges from -10V to 300V DC)
    • Digital input
      NPN (2 and 3 wire)/PNP (2 wire only) open collector (0–2000.0Hz)
    • Potentiometer input (<1kΩ to 20kΩ)
    • AC current sensor input (ACCS-010/ACCS-420)

    Other features:

    • Universal AC/DC power supply (24-250V AC, 19.5-250V DC) – no header adjustments required!
    • Optional relay outputs, ideal for alarming and simple on/off control
    • Optional isolated 4–20mA output, making the Merlin ideal for use as a PLC/SCADA accessory
    • 22V excitation to power two wire transmitters
    • Flexible 32 point linearization table

    Easy, USB Powered Programming

    Simple & Flexible Input/Output Setup The unit boasts a 1 minute setup time using the Define Toolbox configuration software. All functions and features are explained expertly in the dynamic sidebar help - perfect for the novice starting out who can use it to learn about industrial sensors and applications, or the expert who wants to save commissioning time.

    MER-UV, MER-UV-R2A, GF40-HV, GF40-HV-R2A, GF40-LV, GF40-LV-R2A
    Universal Input
    Number of universal inputs
    Accepts Thermocouple, RTD, NTC, Current, Voltage, Digital Pulse, Potentiometer & AC Current sensor
    (See below for full specifications for each input type)
    Power supply
    24-250V AC / 19.5-250V DC, 47-63Hz, 6VA max
    2,300Vrms for 1min to all inputs and outputs
    Thermocouple Input
    Thermocouple types

    K: -328 to 2502°F (-200 to 1372°C)
    B: 752 to 3272°F (400 to 1800°C)
    E: -328 to 1472°F (-200 to 800°C)
    J: -328 to 1832°F (-200 to 1000°C)
    R: -58 to 3200°F (-50 to 1760°C)
    S: -58 to 3200°F (-50 to 1760°C)
    T: -328 to 752°F (-200 to 400°C)
    N: -328 to 2372°F (-200 to 1300°C)
    Input impedance
    1MΩ min
    T/C lead resistance
    100Ω max
    Cold junction compensation
    -14 to 158°F (-10 to 70°C)
    CJC error
    < ±2°C
    E, J, K, N, T: < ±1°C. B, R, S: < ±2°C.
    Ambient drift
    E, J, K, N, T: < ±0.05°C/C. B, R, S: < ±0.2°C/C.
    Sensor break output drive
    Function high upscale/low downscale
    Response time
    RTD Input
    RTD input type
    PT100 or PT1000 DIN 3-wire type (2-wire can be used with off set trim)
    Lead wire resistance

    PT100: 50Ω/wire max. 0.02% FSO off set error per Ω of lead resistance mismatch
    PT1000: 20Ω/wire max. 0.002% FSO off set error per Ω of lead resistance mismatch
    Sensor current
    0.3mA nominal
    Sensor break output drive
    Function high upscale/low downscale
    Better than 0.2°C
    Ambient drift
    Response time
    NTC Input
    10K Beta 3984: -67 to 257°F (-55 to 125°C)
    10K Beta 3435: -58 to 230°F (-50 to 110°C)
    Response time
    Better than 0.4°C
    Ambient drift
    Current Input
    +22V DC, 25mA max
    USB programmable zero
    0–±99% of span
    Field programmable span
    1μA–24mA DC
    Input impedance
    Max over-range
    50mA DC continuous
    Linearity & repeatability
    <±0.02% FSO typical
    Ambient drift
    Response time
    Voltage Input
    Millivolts: ±200mV, –200mV to 1V
    Volts: 0–10V, ±10V, –10 to 30V, 0–300V
    USB programmable zero
    0–±99% of span
    USB programmable span
    95% of FSO
    Input impedance
    1MΩ min
    Linearity & repeatability
    0–10V: <±0.05% FSO
    0–300V: <±0.1% FSO. All other ranges: <±0.02% FSO typical
    Ambient drift
    Response time
    Digital Pulse Input
    Frequency range
    Open collector NPN (2 and 3 wire)/PNP (2 wire only)
    +22V DC, 25mA max
    Response time
    Software modes
    General frequency, Flow rate (pulse), or RPM (pulse)
    Linearity & repeatability
    Ambient drift
    AC Current Sensor Input
    Sensor type
    Current transformer (ACCS-420(-L)/ACCS-010)
    Amperage range
    Header selectable
    ACCS-420/010 = 100/150/200A
    ACCS-420-L = 10/20/50A
    ACCS-420/010 = 175/300/400A respectively
    ACCS-420-L = 80/120/200A respectively
    (Representing 0–100% of full scale input range) ACCS-420 = 4–20mA DC loop powered
    ACCS-010 = 0–10V DC
    Power supply
    ACCS-420(-L) = Loop powered, 15–36V DC
    ACCS-010 = Self powered
    1% of full scale
    Response time
    250ms (10–90%)
    Isolation voltage
    Potentiometer Input
    Potentiometer input
    Excitation voltage
    <1kΩ low pot; 1–4kΩ med pot; 4–20kΩ high pot
    Potentiometer resistance
    Field programmable zero
    0–90% of span
    Field programmable span
    Linearity & repeatability
    <±0.05% FSO typical
    Response time
    Ambient drift
    Relay Output
    Number of relay outputs
    2 (R2A model)
    Relay output type
    Form A
    Isolation to sensor and user input commons: 2,300Vrms for 1min. Working voltage 240Vrms
    Contact rating
    One Relay energized: 3amps at 120/240V AC or 28V DC (resistive load). 3amps max total current with both relays energized
    Life expectancy
    100K cycles min at full load rating
    Analog Output (Retransmission)
    Number of analog outputs
    1 (R2A model)
    Analog output type
    Self-powered (active) 4-20mA or 20-4mA DC
    Isolated to sensor and user input commons
    Isolation test voltage
    1,400Vrms for 1min. Working voltage 125V.
    0.05% of FSO
    Max output drive
    20mA (600Ω max load at 12V DC)
    User Input
    Number of user inputs
    1 (R2A model). Can be programmed for manual relay reset, latching, or zero functions
    Max continuous input
    20V DC
    User input isolation
    Not isolated to sensor input common
    Define ToolBox
    USB programmable using Define ToolBox (Bridge Key required)
    Display type
    0.8" (20mm) red LED, 7-segment characters
    LED indicators
    2 x setpoint indicator LED’s (R2A model only)
    Full scale range
    -1999 to 9999
    Panel mount enclosure. Installation Category II, Pollution Degree 2. Flame resistant. Panel gasket and mounting clips included.
    Ingress protection rating
    IP65 indoor use. (Face only, when mounted according to manufacturer’s instructions)
    Dimensions (H x W x D)
    1.89 x 3.74 x 2.44" (48 x 95 x 62 mm)
    6.87oz (195g)
    Cutout area
    1.77 x 3.62" ±.02 (45 x 92mm ±.5)
    Space behind panel
    3.15" (80mm) minimum space required behind panel (includes space for connectors/wiring)
    Environmental Conditions
    Operating temperature
    14 to 122°F (-10 to 50°C)
    Storage temperature
    -4 to 140°F (-20 to 60°C)
    Operating humidity
    5-85%RH max (non-condensing)
    Up to 2,187yd (2,000m)
    Certifications & Compliances
    EN 61326-1
    Immunity to Industrial Locations
    CISPR 11 Class A (EN 61326)
    Safety requirements for electrical equipment for measurement control and laboratory use
    EN 61010-1 General Requirements, EN 61010-2-030 Particular Requirements for Testing and Measuring Circuits
    UL listed
    File Number E473114

    Merlin Manual Merlin Manual 17V02, 20-Jun-2017 | (1747 KB)

    Merlin Datasheet Merlin Datasheet 17V04, 19-Jun-2017 | (221 KB)

    Define ToolBox

    Define ToolBox

    Smart, simple software to program your non-Zen series products

    Use Define ToolBox software to program your non-Zen series product via your PC. It configures:

    It offers a simple interface for connecting to your compatible device, and a range of flexible configuration options, including an extensive library of pre-calibrated ranges and linearization tables for advanced scaling.

    -UV 24-250V AC / 19.5-250V DC
    Output (Optional)
    -R2A 2 x relay outputs (PLUS 1 x User input for relay reset or latching)
    1 x 4-20mA analog output
    Sample order codes: MER-UV or MER-UV-R2A
    Merlin (No Output)

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