3595-1C1 – 20 Channel Analogue Reed Relay IMP Replacement of 3595-1C IMP

No longer available. For information purposes only.



The 3595-1C1 is a replacement for the original 3595-1C unit, which is proving compatible with the original for applications encountered so far. It has similar measurement ranges and accuracies to the original product and offers enhanced measurement resolutions and additional integration times on a per-channel basis.

The 3595-1C1 also supports improved drift correct measurement options, without compromising compatibility.

It is compatible with the SNET communications and power supply features of the original product and operates on a network-driven from a 3595-4C for example.

It is the same size, has identical fixing positions, and has interchangeable connector blocks with the original product.


  • Compatible Communications with 3595 series.
  • Compatible enclosure and connector blocks.
  • Thermocouple, resistance, RTD, voltage and current measurements in a rugged enclosure.
  • 20 Channels per Module – precision reed relay isolation. Individually programmable.
  • Precision 3 and 4 wire resistance and RTD measurements. (3595-1Q1)
  • Enhanced 14 to 19/20 bit resolution. 100 to 10 measurements per second.
  • Enclosed connector blocks. Dual sensor accurate Cold Junction Compensation.
  • Thermocouple health monitoring Temperatures in °C or °F unit.


Number of channels / module: 20/10

Number of poles / channel: 3/6

Connector type input channels: Standard 3595 series isothermal Enclosure Screw Terminals.

Measurement modes: V DC (mV, DC, uVDC) Thermocouple CJC temperature.

Sensor health: Thermocouple types K,J,T,R,S,E,B,N

Thermocouple compensation: Dual sensors

Current Measurement

Sensitivity ( 100R shunt fitted): <10nA

Accuracy as for voltage ranges + shunt accuracy.

A-D Converter

Measurement resolutions supported:

19/20 bits at 9 measurements/s
18/19 bits at 20 measurements/s
17 bits at 30 measurements/s
15 bits at 80 measurements/s
14 bits at 100 measurements/s
A number of bits includes a sign counted as 1 bit.
50 Hz Mains frequency interference rejection is provided by 17 and 20-bit modes 60 Hz mains interference rejection is provided by 17,19 and 20-bit modes.

Higher Measurement rates possible by disabling drift correct measurements.

Interference Rejection

AC 50/60Hz

Common mode rejection ratio channel group: <0.1uV/V

Single-channel common-mode rejection ratio: <1uV/V

Series mode rejection ratio 50 or 60 Hz +/- 0.05%: <1uv/V

Note: reed scanners are not suitable for direct connection to power circuits.

Voltage measuring mode

Input voltage ranges:


+2,0V >-2.0V

+200mV >-200mV

+30mV >-30mV

Automatic range selection is supported.

Temperature coefficients DC voltage: 25ppm rdg + 0.1uV/o C

Measurement sensitivity 30mV range 18 bits: <0.25uV

Additional error at 80 & 100/sec mode 0.03% of range.

Overload Protection

Channel overload protection: Passive 50V Continuous


For protection against transients and ground loops.

Isolation test voltage IMP to IMP or to SNET: Tested at 500V

Power Requirement


Connector: Via SNET cable

Voltage: 11 to 48V

Current: <100mA at 12V, <50mA at 24V

Thermocouple Measurement Accuracy

Internal Cold junction compensation errors included: (External compensation is also available)

K-100 to 5000.05°C
500 to 12000.7
J1200 to 16003.0
360 to 8000.5
T-150 to 4000.7
R0 to 16000.5
S0 to 17002.0
E-50 to 2902.2
290 to 10000.7
B200 to 16001.0
N-200 to 16004.5
-100 to 5801.1.5
80 to 13001.3

Displayed sensitivity: <0.1oC

Thermocouple Health Monitoring automatic by resistance measurement sequence.

SNET Interface: SNET standard compatible

Status LED’s: 4

Function: Power, Communication, ADC fault, Calibration error

Safety: EN61010-1:2010, EN61010-2-30:2010

EMC: EN55011:2009, EN 61326-2-1:2006

Case size: 435*215*34.5mm

Protrusion of cable boots: 45mm

Weight: 3.23kg

Operating Temperature Range: -20 to 70 °C

Relative Humidity(non condensing): 85% at 40°C

Vibration: 1g 10hz to 400Hz in 3 planes.

Programming storage: Secure flash memory

Calibration temperature is 21°C



Install Guide: [IMP Install Guide]