Supported Applications
The Omega CL540A and CL540ZA series are portable thermocouple sources designed for checking and calibrating thermocouple instruments. These handheld devices provide a simulated thermocouple signal in temperature units (°C or °F) or millivolts, enabling field verification of instrumentation.
Operating Conditions & Performance
The CL540ZA series operates with an accuracy of ±0.1 °C and offers a resolution of 0.1 °C or 0.001 mV. The measurement range spans from 0 to 1000 °C (0 to 1832 °F). Power is supplied by four 1.5V 'AA' Alkaline batteries, which are included with the unit.
Low battery conditions are indicated by a 'BAT' display message. Approximately one to four hours of typical operation remain before the unit automatically turns off if configured for auto-off functionality.
Configuration Options
The CL540ZA model includes additional configuration options compared to the base CL540A, including selectable thermocouple types and an auto-off feature. The series supports a rugged design with low profile switches and offers an optional rubber boot for enhanced protection.
Thermocouple Types (CL540ZA Only)
• J
• T
• E
• K
• R
• S
• B
• N
• G
• C
• D
• L (J-DIN)
• U (T-DIN)
• Platinel II
• mV
Outputs and Connections
The device provides output signals in °C, °F, or millivolts. Electrical connections include a female miniature thermocouple connector at the top end for sensor simulation and two banana jacks at the top end for millivolt signals.
Key Product Differences
The CL540ZA model distinguishes itself from the CL540A by offering selectable thermocouple types (J, T, E, K, R, S, B, N, G, C, D, L, U, Platinel II) and an auto-off feature. Both models utilize four AA batteries; however, removing the batteries resets all stored configuration options—including T/C Type and HI/SET/LO Memories—to factory settings.
Configuration parameters such as EXIT (15), TEMP UNITS (°C), T/C type (K default), and AUTO OFF status are managed via a Configuration Menu. The CL540ZA model specifically supports the expanded list of thermocouple types listed above, whereas the base series identity focuses on general thermocource simulation.
| Accuracy | ± 0.015 % |
| Accuracy Detail | ± (0.015% of reading + 0.006 mV) |
| Additional Features 1 | Source Only |
| Battery Indication | A low battery indication is displayed when the battery voltage drops below the operating level |
| Battery Life | 50 hr |
| Cold Junction Compensation | ± 0.25°C |
| Dimensions (Boot) | 144 L x 78 W x 52 D mm |
| Display Type | LCD |
| Display Type Note | High contrast graphic liquid crystal display, LED backlighting for use in low lit areas |
| Height | 45 mm |
| Length | 126 mm |
| Operating Temperature, Min | -25 °C |
| Over-Voltage Protection | Over-voltage protection to 60 Vdc (rated for 30 seconds) |
| Relative Humidity, Max | 0.9 |
| Relative Humidity, Min | 10% |
| Relative Humidity Note | 10% ≤ RH ≤ 90% 0 to 35°C (32 to 95ºF), non-condensing. 10% ≤ RH ≤ 70% 35 to 60°C (95 to 140ºF), non-condensing |
| Series ID | CL540ZA-series |
| Supply Voltage | 6 Vdc |
| Thermocouple Type | J, K, T, E, N, R, S, U, B, G, C, D, L |
| Voltage Source | Output Impedance: < 0.3 Ω Source Current: > 20 mA (drives 80 mV into 10 Ω) Noise: ≤ 4 microvolts p-p for frequencies of 10 Hz or below |
| Weight | 238 g (8.4 oz) (including batteries) |
| Weight(boot) | 311.8 g (11 oz) (including batteries) |
| Width | 69 mm |