Detailed Sensor Input Specifications

0 to 5 Volt Single Ended Input

• High Accuracy, 12-Bit Successive Approximation Register type Analog-to-Digital Converter
• 1.2 millivolt measurement resolution for input range from 0.020 volts to 4.980 volts
• Input Impedance >1 MOhm
• Input Offset Voltage less than 1.0 millivolt
• Single ended operating mode, the low-side input must be connected to system ground
• Single Ended Mode - Input Signal Must be Between 0 and +5 volts. Measurement Must Be Referenced to Ground. That is the low side of the signal must be connected to ground.

4 to 20 mA Current Loop Receiver

• Measurement Resolution – 5uA
• Optically Isolated Interface – Inputs Isolated with UL1577 Recognized components (5KV rms/1 min)
• Compliant with input signals driven by voltage levels from 9 to 50 volts
• Corrected for improved linearity
• 4 - 20 milliAmp Analog Signal Monitor - Electrical isolation provided by optoelectronic isolator. High and low side isolated. Maximum peak current must be below 40 milliamps, maximum reverse voltage should be less than 2.5 volts.

-2.5 Volt to 2.5 Volt Differential Mode Input

• Highest Accuracy using a 24-bit “Delta-Sigma” type Analog-to-Digital Converter
• 75 microvolt measurement resolution
• Input Impedance >1 MOhm
• Differential Mode voltage difference can range from –2.5 to +2.5 volts
• Absolute voltage must be between 0.05 and +3.5 volts. No negative voltage relative to system ground is allowed on this channel.
• Differential operating mode, the measurement reflects the difference between the voltage on the two connections. Neither side must be connected to ground.
• Suitable for bridge circuit applications such as common strain gage circuit configurations.
• Input Signals Must be Between 0 and + 5 volts. Difference in Signal Voltage Must be Between -2.5 volts and +2.5 volts.

-10 Volt to +10 Volt Single Ended Mode Input

• Largest dynamic range input on NEEM from –10 volt to + 10 volts
• 5 millivolt resolution
• Input Impedance >1 MOhm
• Single ended operating mode, the low-side input must be connected to system ground
• Single Ended Bipolar Mode - Input Signal Must be Between -10 volts and +10 volts. Measurement Must Be Referenced to Ground. That is the low side of the signal must be connected to ground.

Event Counter

• 5 User Selectable Discrete Counting Intervals including 1.0 seconds, 20 seconds, 60 seconds (1-minute), 600 seconds (10-minutes), 3600 seconds (60-minutes), and Continuous Mode
• In the Continuous Mode counting resumes with last counted value when power to the NEEM unit is cycled off and then on again.
• Maximum Count Rate 100,000 events/second
• Maximum Count Value equal 32,767
• Timing Calibration Accuracy for 1 second interval +/- 0.05%
• Standard CMOS logic level inputs
  • Logic Low Input less than 0.8 volts Logic High Input greater than 2.4 volts
  • Maximum 5 volt input
• Signal Must be a Pulse from 0 to +5 volts (TTL Level Pulses). - Minimum pulse width is 1.0 microseconds. Event counter voltage signal high level must be greater than 2.5 volts to be recorded as a count.

Thermocouple Measurements

• Includes Type K (Chromel-Alumel) Thermocouple Input Standard for User Supplied Type K Thermocouple Probes
• 1 oC Measurement Resolution for measurements greater than –40 oC
• Approximately 2 oC Measurement Accuracy
  • Absolute Measurement Accuracy Limits Due to Errors that Depend on the Composition Variations in User Supplied Type K Thermocouple Probe -Typically greater of 2.2oC or 0.75% for measurements above 0oC
• Measurements over Entire Useful Range of Type K Thermocouple
• Measure Temperatures Below -200 oC to Greater than +1200 oC
  • Actual Upper and Lower Measurement Limit Will Depend on the Construction Details of the User Supplied Type K Thermocouple
• Universal Type K Thermocouple Connector
  • Combination Standard/Miniature Type K Front Panel Connector
• Other types of thermocouples (J & E) available upon request
• Thermocouple Signal - Thermocouple Signal must Not be Referenced to Ground. Neither the plus side or the minus side of the thermocouple signal should be directly connected to ground. No common mode voltage should be present on this signal.

On-Board Real Time Clock

• Real Time Clock Information Available including Year, Month, Day, Date, Hours, Minutes, Seconds
• Battery Back-Up for Clock, Nominal Battery Lifetime Exceeds 10 years
• Typical Accuracy +/- 2 seconds/day

Internal Temperature for Measurement Reference and Monitoring NEEM Environment

• Approximate internal temperature of the NEEM unit
• Silicon diode type of temperature sensor on the NEEM circuit board provides the temperature in degrees Celsius for one area of the main circuit board.
• Internal Temperature - This sensor is internally connected to provide a coarse measure of the NEEM-1112 circuit board temperature. No user connection allowed for this channel.

Switch Input Interface for Dry Contact Switch

• Monitors “dry” switch contacts – 5 volts and 1 milliamp sense current.
• “Low –side” electrical contact connected directly to system ground.
• Monitors the state of a dry contact switch. In the open state, the switch must stand-off 5 volts. In the closed state, the switch must conduct 1 milliamp of current.

0 or 5 Volt Output Signal Interface

• Remotely Activated by the NEEM-112 Unit
• Output High Voltage > 4.5 volts referenced to NEEM Ground
• Output High Current > 1.0 milliamps
• Output Low Voltage < 0.5 volts referenced to NEEM Ground
• Output Low Current < 1.0 milliamps
• Control Output Signal - O volts or 5 volts output. Output signal will supply up to 1 milliamp at 4.5 to 5.0 volts and will sink up to 1 milliamp at 0 to 0.5 volts.