Robertshaw Stud Sensor 158A User Manual

  

 

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1.1 GENERAL 

The Robertshaw Model 158A Level-Tel is a 
capacitance operated DC current transmitter with 
noninteracting and independent zero and span 
adjustments internally located.  The transmitter is 
remotely mounted from the probe with a triax 
cable interconnected between the probe and the 
transmitter. 
 
1.2 MODEL 

IDENTIFICATION 

Identify instrument models in accordance with the 
descriptions and variations listed in each table. 
 

158A  -  B  1  -  A  1 

Key Model No. 

Table 1 – Output Current 

Table 2 – Supply Voltage 

Table 3 – Display Housing and Indication 

Table 4 – Alarm Options 
 
 

158A Capacitance-to-current 

transmitter 

system for remotely mounted probe 
assemblies.  Control Unit is 
available with or without indication 
and optional alarms. 

 
 

A 1-5 

mADC 

B 4-20 

mADC 

C 10-50 

mADC 

D 0-10 

mADC 

 
 

1 

26.5 VDC, 

± 10% 

2 

120 VAC, 

± 10%, 50/60 Hz 

3 

240 VAC, 

± 10%, 50/60 Hz 

 
 
 

A 

Water tight enclosure without 
indicator. 
Meets NEMA Type 4 and CSA 
Enclosure 5. 

B 

Water tight housing with indicator. 
Meets NEMA Type 4 and CSA 
Enclosure 5. 

C 

Explosion proof housing without 
indicator. 
For Class I, Division 1, Groups C 
and D; Class II, Division 1, Groups 
E, F and G, areas. 

D 

Explosion proof housing with 
indicator. 
For Class I, Division 1, Groups C 
and D; Class II, Division 1, Groups 
E, F and G, areas. 

E 

Large weatherproof enclosure with 
indicator to be used with optional 
alarms. 
Meets NEMA Type 12 & 13 and 
CSA Encl 3. 

 
 

1 None 
2 

¾Alarm Relays for High or Low 
Alarm. 

3 

¾Alarm Relays for High and Low 
Alarms. 

¾ May only be used with Designation E on 
 Table