Universal Trip Amplifier – PR Electronics 4131


  • Input for RTD, TC, Ohm, potentiometer, mA and V
  • 2 adjustable alarm limits
  • FM-approved for installation in Div. 2
  • 2 relay outputs
  • Universal AC or DC supply

Advanced features

  • Programmable via detachable display front (4501), process calibration, relay simulation, password protection, error diagnostics and selection of help text in several languages.


  • Process control with 2 pairs of potential-free relay contacts which can be configured to suit any application.
  • Trip amplifier with window function defined by a high and a low setpoint. The relay changes state outside the window.
  • Relay latch function, where the relay is activated and can only be reset manually.
  • Sophisticated sensor error surveillance, where one relay holds the state immediately prior to the sensor error, while allowing the process to continue. The other relay can be set for sensor error alarm so that the defect sensor can be replaced immediately.

Technical characteristics

  • When 4131 is used with the 4501 display / programming front, all operational parameters can be modified to suit any application. As the 4131 is designed with electronic hardware switches, it is not necessary to open the device for setting of DIP-switches.
  • A green front LED indicates normal operation and malfunction. A yellow LED is ON for each active output relay.
  • Continuous check of vital stored data for safety reasons.
  • 3-port 2.3 kVAC galvanic isolation.


Operating temperature -20°C to +60°C
Calibration temperature 20…28°C
Relative humidity < 95% RH (non-cond.)
Protection degree IP20
Dimensions (HxWxD) 109 x 23.5 x 104 mm
Dimensions (HxWxD) w/ 4501/451x 109 x 23.5 x 116 / 131 mm
Weight approx. 170 g
Weight incl. 4501 / 451x (approx.) 185 g / 200 g
Wire size 0.13…2.08 mm2 AWG 26…14 stranded wire
Screw terminal torque 0.5 Nm
Vibration IEC 60068-2-6
2…13.2 Hz ±1 mm
13.2…100 Hz ±0.7 g
Supply voltage, universal 21.6…253 VAC, 50…60 Hz or 19.2…300 VDC
Fuse 400 mA SB / 250 VAC
Max. required power ≤ 2.0 W
Max. power dissipation ≤ 2.0 W
Isolation voltage
Isolation voltage, test / working 2.3 kVAC / 250 VAC
Response time
Temperature input (0…90%, 100…10%) ≤ 1 s
mA / V input (0…90%, 100…10%) ≤ 400 ms
Auxiliary supplies
2-w. supply (term. 44…43) 25…16 VDC / 0…20 mA
Programming PR 45xx
Signal / noise ratio Min. 60 dB (0…100 kHz)
Accuracy Better than 0.1% of sel. range
EMC immunity influence < ±0.5% of span
Extended EMC immunity: NAMUR NE21, A criterion, burst < ±1% of span
RTD input
RTD type Pt10/20/50/100/200/250; Pt300/400/500/1000; Ni50/100/120/1000; Cu10/20/50/100
Cable resistance per wire 50 Ω (max.)
Sensor current Nom. 0.2 mA
Effect of sensor cable resistance (3-/4-wire) < 0.002 Ω / Ω
Sensor error detection Yes
Short circuit detection < 15 Ω
Linear resistance input
Linear resistance min….max. 0 Ω…10000 Ω
Potentiometer input
Potentiometer min….max. 10 Ω…100 kΩ
TC input
Thermocouple type B, E, J, K, L, N, R, S, T, U, W3, W5, LR
Cold junction compensation (CJC) via ext. sensor in 5910 20…28°C ≤ ±1°C, -20…20°C / 28…70°C ≤ 2°C
CJC via int. mounted sensor ±(2.0°C + 0.4°C * Δt)
Δt = Internal temp.-ambient temp.
Sensor error detection Yes
Sensor error current: When detecting / else Nom. 2 μA / 0 μA
Current input
Measurement range 0…23 mA
Programmable measurement ranges 0…20 and 4…20 mA
Input resistance Nom. 20 Ω + PTC 50 Ω
Voltage input
Measurement range 0…12 VDC
Programmable measurement ranges 0/0.2…1, 0/1…5, 0/2…10 VDC
Input resistance Nom. 10 MΩ
Relay output
Relay functions Setpoint, Window, Sensor error, Latch, Power and Off
Hysteresis 0…100%
ON and OFF delay 0…3600 s
Max. voltage 250 VRMS
Max. current 2 AAC or 1 ADC
Max. AC power 500 VA
Sensor error reaction Break / Make / Hold
of span = of the currently selected measurement range
EMC 2014/30/EU
LVD 2014/35/EU
RoHS 2011/65/EU
EAC TR-CU 020/2011
EAC LVD TR-CU 004/2011
c UL us, UL 508 / C22.2 No. 14 E231911
FM 3025177
DNV-GL Marine TAA0000101
EU RO Mutual Recognition Type Approval MRA000000Z


PR Electronic 4131 Universal trip amplifier-DpstarGroup